June 18, 2024

Outreachy Internship Blog Series: My Self Introduction

Hi! I’m Udo Ijibike, and I’m currently participating in a GNOME UX research project this summer as an Outreachy intern. My mentors are Allan Day and Aryan Kaushik. This is the first in a series of blog posts chronicling my internship.

About Me

I’m a passionate User Experience (UX) Designer from Nigeria. I love technology, and despite my degree in engineering, I’ve always had an appreciation for the arts and a keen interest in psychology. These seemingly disparate interests ultimately converge through UX Design in a way that’s incredibly fulfilling for me.

My core values include self-awareness, progress, and curiosity. Self-awareness helps me set meaningful goals, focusing on progress keeps me grounded enough to enjoy the process, and curiosity keeps me open to new ideas.

Why I Applied to Outreachy

Outreachy is a platform that advocates for everyone’s potential to contribute meaningfully to science and technology, and its goal validates my aspirations as a UX Designer. I discovered Outreachy four months into my pivot to UX Design. This early in my transition, doubts were frequent, but learning about Outreachy strengthened my resolve to persevere.

It took a few rounds of deliberation before I mustered the courage to apply. I feel honored to have been selected as an intern on my second attempt.


The internship application had two stages: the initial application and the contribution period. Getting through the initial application was significant, but it was just the first step. However, I saw the opportunity to contribute to an impactful project and work with a mentor for an entire month as invaluable for learning. Therefore, I approached the contribution phase resolved to find a project where I could contribute and improve my UX Design skills in a meaningful way.

I was drawn to GNOME because of its design-driven approach to solving complex problems in Free and Open Source Software. Its commitment to user-friendliness and inclusivity in FOSS made an impression on me, and the internship project itself was an ideal match for my objectives.

Internship Project

My internship project focuses on understanding user needs through UX research to enhance the usability of GNOME software.

Over the next few months, we’ll be conducting user interviews, surveys, and user tests to derive actionable insights for improving select software within the GNOME ecosystem.

Looking Forward

I’m thrilled to be learning so much from contributing to a project that I’m excited about in such a welcoming community. As my internship continues, I’ll continue to share more about my Outreachy experience and our project in subsequent posts.

Thank you for reading!

Update on Newton, the Wayland-native accessibility project

Several months ago, I announced that I would be developing a new accessibility architecture for modern free desktops. Now, I’m happy to provide an update on this project, code-named Newton. Before I begin, I’d like to thank the Sovereign Tech Fund for funding this work, and the GNOME Foundation for managing the contract.

A word on the name

When choosing a working name for this project, I decided to follow the convention established by Wayland itself, and followed by a couple of other projects including the Weston compositor, of naming Wayland and related projects after places in New England. Newton, Massachusetts is the town where the Carroll Center for the Blind is located.


Here’s a demo of me using a modified GNOME OS image with a couple of GTK 4 apps running inside Flatpak sandboxes without the usual accessibility exception.


Builds for testing

The following builds are based on GNOME 46.2 with my current unmerged Newton modifications. The corresponding Git branches are linked below.

I’ve also built a Flatpak repository, but it isn’t currently signed, so it doesn’t have a .flatpakrepo file. You can add it manually with this command:

flatpak remote-add --user --no-gpg-verify newton https://mwcampbell.us/gnome/gnome-46-newton/repo/

Because the Flatpak repository is based on GNOME 46, you can use Flatpak apps that were built for GNOME 46 with the Newton version of the org.gnome.Platform runtime. You can install that runtime with this command:

flatpak install newton org.gnome.Platform

Source repositories

Here are the links to the unmerged Newton branches of the individual components:

Here are my branches of the Buildstream metadata repositories, used to build the GNOME OS image and Flatpak runtime:

freedesktop-sdk gnome-build-meta

Only this last repository needs to be checked out directly. With it, one should be able to reproduce my builds.

If you want to do your own builds of the relevant components, my addition to the Orca README has instructions. The Orca GitLab project linked above is also a good place to provide end-user feedback.

What’s working so far

I’ve now implemented enough of the new architecture that Orca is basically usable on Wayland with some real GTK 4 apps, including Nautilus, Text Editor, Podcasts, and the Fractal client for Matrix. Orca keyboard commands and keyboard learn mode work, with either Caps Lock or Insert as the Orca modifier. Mouse review also works more or less. Flat review is also working. The Orca command to left-click the current flat review item works for standard GTK 4 widgets.

As shown in the recorded demo above, Newton-enabled applications can run inside a Flatpak sandbox without the usual exception for the AT-SPI bus, that is, with the --no-a11y-bus option to flatpak run. Support for such sandboxing was one of the major goals of this project.

The standard GTK text widgets, including GtkEntry and GtkTextView have fairly complete support. In particular, when doing a Say All command, the caret moves as expected. I was also careful to support the full range of Unicode, including emoji with combining characters such as skin tone modifiers.

What’s broken or not done yet

The GNOME Shell UI itself is not yet using Newton, but AT-SPI. The UI is still accessible with the Newton versions of Mutter and Orca, but it’s being accessed via AT-SPI, meaning that performance in this UI is not representative of Newton, and mouse review doesn’t work for this UI.

Synthesizing mouse events isn’t yet supported on Wayland. This means that while the Orca command for left-clicking the current flat review item is expected to work for standard GTK 4 widgets, that command doesn’t work for widgets that don’t support the appropriate accessible action, and the right-click command doesn’t work.

AccessKit doesn’t currently support sentences as text boundaries. This means that Orca’s Say All command fallback so treading by line, leading to unnatural breaks in the speech.

The GTK AccessKit implementation doesn’t yet support out-of-tree text widgets that implement the GtkAccessibleText interface, such as the GTK 4 version of the vte terminal widget. This means that GTK 4-based terminal apps like kgx don’t yet work with Newton. I don’t yet know how I’ll solve this, as the current GtkAccessibleText interface is not a good fit for the push-based approach of AccessKit and Newton.

Text attributes such as font, size, style, and color aren’t yet exposed. AccessKit has properties for these attributes, but the AccessKit AT-SPI backend, much of which is reused by the Newton AT-SPI compatibility library, doesn’t yet support them.

Tables aren’t yet supported. AccessKit has properties for tables, and the GTK AccessKit backend is setting these properties, but the AccessKit AT-SPI backend doesn’t yet expose these properties.

Some states, such as “expanded”, “has popup”, and “autocomplete available”, aren’t yet exposed.

I’m aware that some GTK widgets don’t have the correct roles yet.

When Caps Lock is set as the Orca modifier, you can’t yet toggle the state of Caps Lock itself by pressing it twice quickly.

Orca is the only assistive technology supported so far. In particular, assistive technologies that are implemented inside GNOME Shell, like the screen magnifier, aren’t yet supported.

Bonus: Accessible GTK apps on other platforms

Because we decided to implement Newton support in GTK by integrating AccessKit, this also means that, at long last, GTK 4 apps will be accessible on Windows and macOS as well. The GTK AccessKit implementation is already working on Windows, and it shouldn’t be much work to bring it up on macOS. To build and test on Windows, check out the GTK branch I linked above and follow the instructions in its README. I’ve built and tested this GTK branch with both Visual Studio (using Meson and the command-line Visual C++ tools) and MSYS 2. I found that the latter was necessary for testing real-world apps like gnome-text-editor.

Architecture overview

Toolkits, including GTK, push accessibility tree updates through the new accessibility Wayland protocol in the wayland-protocols repository linked above. The latest accessibility tree update is part of the surface’s committed state, so the accessibility tree update is synchronized with the corresponding visual frame. The toolkit is notified when any accessibility clients are interested in receiving updates for a given surface, and when they want to stop receiving updates, so the toolkit can activate and deactivate its accessibility implementation as needed. This way, accessibility only consumes CPU time and memory when it’s actually being used. The draft Wayland protocol definition includes documentation with more details.

Assistive technologies or other accessibility clients currently connect to the compositor through a D-Bus protocol, defined in the Mutter repository linked above. By exposing this interface via D-Bus rather than Wayland, we make it easy to withhold this communication channel from sandboxed applications, which shouldn’t have this level of access. Currently, an assistive technology can find out about a surface when it receives keyboard focus or when the pointer moves inside it, and can then ask to start receiving accessibility tree updates for that surface.

The same D-Bus interface also provides an experimental method of receiving keyboard events and intercepting (“grabbing”) certain keys. This is essential functionality for a screen reader such as Orca. We had originally planned to implement a Wayland solution for this requirement separately, but decided to prototype a solution as part of the Newton project to unblock realistic testing and demonstration with Orca. We don’t yet know how much of this design for keyboard event handling will make it to production.

The compositor doesn’t process accessibility tree updates; it only passes them through from applications to ATs. This is done using file descriptor passing. Currently, the file descriptors are expected to be pipes, but I’ve thought about using shared memory instead. The latter would allow the AT to read the accessibility tree update without having to block on I/O; this could be useful for ATs that run inside Mutter itself, such as the screen magnifier. (The current Newton prototype doesn’t yet work with such ATs.) I don’t know which approach is overall better for performance though, especially when one takes security into account.

The serialization format for accessibility tree updates is currently JSON, but I’m open to alternatives. Obviously we need to come to a decision on this before this work can go upstream. The JSON schema isn’t yet documented; so far, all code that serializes and deserializes these tree updates is using AccessKit’s serialization implementation.

In addition to tree updates, this architecture also includes one other form of serialized data: accessibility action requests. These are passed in the reverse direction, from the AT to the application via the compositor, again using file descriptor passing. Supported actions include moving the keyboard focus, clicking a widget, setting the text selection or caret position, and setting the value of a slider or similar widget. The notes about serialization of tree updates above also apply to action requests.

Note that the compositor is the final authority on which tree updates are sent to the ATs at what time, as well as on which surface has the focus. This is in contrast with AT-SPI, where ATs receive tree updates directly from applications, and any application can claim to have the focus at any time. This is important for security, especially for sandboxed applications.

Open architectural issues

The biggest unresolved issue at this point is whether the push-based approach of Newton, the motivation for which I described in the previous post, will have unsolvable drawbacks, e.g. for large text documents. The current AccessKit implementation for GtkTextView pushes the full content of the document, with complete text layout information. On my brand new desktop computer, this has good performance even when reading an 800 KB ebook, but of course, there are bigger documents, and that’s a very fast computer. We will likely want to explore ways of incrementally pushing parts of the document based on what’s visible, adding and removing paragraphs as they go in and out of view. The challenge is to do this without breaking screen reader functionality that people have come to depend on, such as Orca’s Say All command. My best idea about how to handle this didn’t occur to me until after I had finished the current implementation. Anyway, we should start testing the current, naive implementation and see how far it takes us.

The current AT protocol mentioned above doesn’t provide a way for ATs to explore all accessible surfaces on the desktop; they can only find out about an accessible surface if it receives keyboard focus or if the pointer moves inside it. A solution to this problem may be necessary for ATs other than Orca, or for automated testing tools which currently use AT-SPI.

The current architecture assumes that each Wayland surface has a single accessibility tree. There isn’t yet an equivalent to AT-SPI’s plugs and sockets, to allow externally generated subtrees to be plugged into the surface’s main tree. Something like this may be necessary for web rendering engines.

I’m not yet sure how I’ll implement Newton support in the UI of GNOME Shell itself. That UI runs inside the same process as the compositor, and isn’t implemented as Wayland surfaces but as Clutter actors (the Wayland surfaces themselves map to Clutter actors). So the existing AccessKit Newton backend won’t work for this UI as it did for GTK. One option would be for Mutter to directly generate serialized tree updates without going through AccessKit. That would require us to finalize the choice of serialization format sooner than we otherwise might. While not as convenient as using the AccessKit C API as I did in GTK, that might be the least difficult option overall.

Newton doesn’t expose screen coordinates, for individual accessible nodes or for the surfaces themselves. ATs are notified when the pointer moves, but the compositor only gives them the accessible surface ID that the pointer is inside, and the coordinates within that surface. I don’t yet have a solution for explore-by-touch, alternative input methods like eye-tracking, or ATs that want to draw overlays on top of accessible objects (e.g. a visual highlight for the screen reader cursor).

Next steps

The earlier section on what’s broken or not done yet includes several issues that should be straightforward to fix. I’ll fix as many of these as possible in the next several days.

But the next major milestone is to get my GTK AccessKit integration reviewed and merged. Since Newton itself isn’t yet ready to go upstream, the immediate benefit of merging GTK AccessKit support would be accessibility on Windows and macOS. The current branch, which uses the prototype Newton backend for AccessKit, can’t be merged, but it wouldn’t be difficult to optionally support AccessKit’s AT-SPI backend instead, while keeping the Newton version on an unmerged branch.

The main challenge I need to overcome before submitting the GTK AccessKit integration for review is that the current build system for the AccessKit C bindings is not friendly to distribution packagers. In particular, one currently has to have rustup and a Rust nightly toolchain installed in order to generate the C header file, and there isn’t yet support for installing the header file, library, and CMake configuration files in FHS-compliant locations. Also, that build process should ideally produce a pkg-config configuration file. My current gnome-build-meta branch has fairly ugly workarounds for these issues, including a pre-generated C header file checked into the repository. My current plan for solving the nightly Rust requirement is to commit the generated header file to the AccessKit repository. I don’t yet know how I’ll solve the other issues; I might switch from CMake to Meson.

The other major thing I need to work on soon is documentation. My current contract with the GNOME Foundation is ending soon, and we need to make sure that my current work is documented well enough that someone else can continue it if needed. This blog post itself is a step in that direction.

Help wanted: testing and measuring performance

I have not yet systematically tested and measured the performance of the Newton stack. To be honest, measuring performance isn’t something that I’m particularly good at. So I ask that Orca users try out the Newton stack in scenarios that are likely to pose performance problems, such as large documents as discussed above. Then, when scenarios that lead to poor performance are identified, it would be useful to have someone who is skilled with a profiler or similar tools help me investigate where the bottlenecks actually are.

Other desktop environments

While my work on Newton so far has been focused on GNOME, I’m open to working with other desktop environments as well. I realize that the decision to use D-Bus for the AT client protocol won’t be universally liked; I suspect that wlroots-based compositor developers in particular would rather implement a Wayland protocol extension. Personally, I see the advantages and disadvantages of both approaches, and am not strongly attached to either. One solution I’m considering is to define both D-Bus and Wayland protocols for the interface between the compositor and ATs, and support both protocols in the low-level Newton client library, so each compositor can implement whichever one it prefers. Anyway, I’m open to feedback from developers of other desktop environments and compositors.


While the Newton project is far from done, I hope that the demo, builds, and status update have provided a glimpse of its potential to solve long-standing problems with free desktop accessibility, particularly as the free desktop world continues to move toward Wayland and sandboxing technologies like Flatpak. We look forward to testing and feedback from the community as we keep working to advance the state of the art in free desktop accessibility.

Thanks again to the Sovereign Tech Fund and the GNOME Foundation for making this work possible.

Status update, 18th June 2024


If you’re into podcasts, the Blindboy Podcast is possibly the best one. Recent episode The State of the World begins on a pointy rock off the coast of Ireland that houses a 6th century monastery.

Photo of Skellig Michael
Skellig Michael – Photo credit – Tristan Reville

Then he raises the question of why, when the Russian government & the Russian military commit war crimes, US & European leaders apply punishing economic sanctions to Russia, and when the government and the military of Israel commit atrocities and war crimes, US & European leaders ask them nicely if they could please stop at some point, or at least commit slightly fewer of them.

On that note, I’d like to shout out the Bands Boycott Barclays movement in the UK — our politicians have failed, but at least our musicians aren’t afraid to follow the money and stand up for human rights.

Heisenbugs and spaghetti code

In computer programming jargon, a heisenbug is a software bug that seems to disappear or alter its behavior when one attempts to study it. (Wikipedia)

In the year 2018 I was passing time in Barcelona waiting to start a new job (and a new life, as it turned out). It was the middle of July and everyone had left for the summer. Meanwhile GNOME had recently gained a Gitlab instance and for the first time we could run automated test pipelines in Gitlab CI, so I set up initial CI pipelines for Tracker and Tracker Miners. (Which, by the way, are undergoing a rename).

Tracker Miners already has a testsuite, but in 2018 it was only run when someone decided to run it locally. Remember that our filesystem indexer is implemented as many GIO async callbacks, which means it is complex spaghetti code. These callbacks can fire in a different order depending on various factors. Tracker responds to filesystem notifications and disk reads, which are unpredictable. And of course, it has bugs — in 2018 nobody much was funding maintenance Tracker or Tracker Miners, and many of these would trigger, or not, depending on the execution order of the internal async callbacks.

So, many of the tests would just randomly fail, making the new CI rather useless.

Thanks to a lot of hard work by Carlos and myself, we documented and fixed these issues and the indexer is in a much better state. It was not much fun! I would rather be eating spaghetti than tracing through spaghetti code. I guess somewhere I made bad life choices.

Bowl of spaghetti

In 2021, somehow not learning my lesson, I adopted the nascent openQA tests for GNOME OS that were developed by one of my Codethink colleagues. These have been running for 3 years now at a “beta” quality service, and have caught some interesting bugs along the way.

In late 2023 we noticed a seemingly random test failure, where the machine under test makes it through initial setup, but didn’t get to a user session. Let’s call this issue 62.

This issue reproduces a lot, when you don’t want it to, and rarely if ever when you do. Here’s a recent example. See how the initial setup stage (gnome_welcome) passes, but the transfer to the final user session never happens:

openQA test result with gnome_desktop test failing

Random test failures make a test framework completely useless – if “test failed” can mean “your code is fine but fate is not on your side today”, then it’s not a useful signal for anyone. So for the GNOME OS automated testing to progress, we need to fix this intermittent failure.

GNOME OS runs many different processes during startup, which can start in whatever order the systemd daemon decides to start them, and can then start child processes of their own. No two boots are exactly the same. The graphical startup is driven by systemd, GDM, gnome-session, gnome-initial-setup and GNOME Shell, context switching between themselves hundreds of times following D-Bus message traffic. You could say that this is an extra large portion of spaghetti, with toxic meatballs.

As part of the STF engagement with GNOME OS, Neill Whillans spent a considerable amount of time comparing logs from good and bad boots, investigating the various processes that run at start-up time, and trying to catch the boot failure locally. I’ve tried my best to help as time permits (which it mostly does not).

Fundamentally, the issue is that there are two gnome-shell processes running, one for the initial-setup user and one for the new ‘testuser’ which should take over the session. GDM is supposed to kill the initial-setup shell when the new ‘testuser’ shell begins. This doesn’t happen.

We have a theory that its something failing during the startup of the new gnome-shell. The layout mechanism looks very complex, so its entirely possible that there is a heisenbug in there somewhere. As you would expect, enabling debug logs for GNOME Shell causes the issue to go away completely.

There’s a lesson here, which is that excessive complexity kills motivation, and ultimately kills projects. We could have done quite a lot in the last 7 months if not for this issue. Let’s all try to keep our code simple, debuggable and documented. We have succeeded in the past at killing overly complex abstractions in GNOME — remember CORBA? Perhaps we need to do so again.

What happens next? I am not sure – I think we may just have to give up on the end-to-end tests for the time being, as we can’t justify spending more of the current budget on this, and I’ve done enough volunteer debugging and documentation efforts for the time being – I plan to spend the summer evenings in a hammock, far away from any GNOME code, perhaps eating spaghetti.

June 17, 2024

Toolbx now enables the proprietary NVIDIA driver

… and why did it take so long for that to happen?

If you build Toolbx from Git and install it to your usual prefix on a host operating system with the proprietary NVIDIA driver, then you will be able to use the driver on all freshly started Toolbx containers. Just like that. There’s no need to recreate your containers or to use some special option. It will just work.

How does it work?

Toolbx uses the NVIDIA Container Toolkit to generate a Container Device Interface specification on the host during the toolbox enter and toolbox run commands. This is a JSON or YAML description of the environment variables, files and other miscellaneous things required by the user space part of the proprietary NVIDIA driver. Containers share the kernel space driver with the host, so we don’t have to worry about that. This specification is then shared with the Toolbx container’s entry point, which is the toolbox init-container command running inside the container. The entry point handles the hooks and bind mounts, while the environment variables are handled by the podman exec process running on the host.

It’s worth pointing out that right now this neither uses nvidia-ctk cdi generate to generate the Container Device Interface specification nor podman create --device to consume it. We may decide to change this in the future, but right now this is the way it is.

The main problem with podman create is that the specification must be saved in /etc/cdi or /var/run/cdi, both of which require root access, for it to be visible to podman create --device. Toolbx containers are often used rootless, so requiring root privileges for hardware support, something that’s not necessary on the host, will be a problem.

Secondly, updating the toolbox(1) binary won’t enable the proprietary NVIDIA driver in existing containers, because podman create only affects new containers.

Therefore, Toolbx uses the tags.cncf.io/container-device-interface Go APIs, which are also used by podman create, to parse and apply the specification itself. The hooks in the specification are a bit awkward to deal with. So, at the moment only ldconfig(8) is supported.

The issue with nvidia-ctk is relatively minor and is because it’s another different binary. It makes error handling more difficult, and downstream distributors and users of Toolbx need to be aware of the dependency. Instead, it’s better to directly use the github.com/NVIDIA/go-nvlib and github.com/NVIDIA/nvidia-container-toolkit Go APIs that nvidia-ctk also uses. This offers all the usual error handling facilities in Go and ensures that the dependency won’t go missing.

Why did it take so long?

Well, hardware support needs hardware, and sometimes it takes time to get access to it. I didn’t want to optimistically throw together a soup of find(1), grep(1), sed(1), etc. calls without any testing in the hope that it will all work out. That approach may be fine for some projects, but not for Toolbx.

Red Hat recently got me a ThinkPad P72 laptop with a NVIDIA Quadro P600 GPU that let me proceed with this work.

GSoC 2024: Week 3 Report

It’s been a while since I have given any updates, so here we are.

I listed down the demos that needed to be ported according to their length (S, M, L depending on the Lines of code)

I planned to work on 3 demos daily, 1 LOC type each, which was different from how it panned out. I’ll attach the list here for it to be more clear for everyone.

Week 1

The first demo I worked on was the Dialog demo. It was straightforward, but one thing that kept confusing me was the package declarations and how to know which packages to include. Only after going through the documentation of the functions that didn't work, did I understand the exact terms to use to declare these packages.

I also added the Python port for this demo, one thing (not specific for this port) but the first time I got to know about was the use of `_parameters` which are parameters that may or may not be used by the function but are still needed by the signal calls.

Actions demo took me some time to understand and implement mostly because of the lack of understanding of how Simple Actions work and the `notify.connect` function parameters. I also needed to make some changes to make the user-visible strings according to the style guide. Another interesting thing was that the Vala formatter checks the surrounding code and then formats the rest of the code. Initially, my code was not being formatted correctly because I had missed a space when declaring the main method.

All of the code improvements/suggestions were given to me by my reviewers Diego Ivan and Lorenz Wildberg. I am thankful to them for going through each of my demo ports (No matter how messy or unclean the code was) and answering all of my questions and doubts. If you’re reading this Diego I’m sorry for my Screencast port.

Okay, the next demo I worked on was CSS Gradients. This was a bigger port and needed the creation of different methods for generating and updating the CSS values. If you need more information about what each demo does, I recommend reading blogs written by Akshay and Sriyansh. This demo uses methods of the Gtk.StyleContext class, the class is deprecated and hence the CLI produces an error when running the checks. Sonny has had to make an exception for it in the CLI to make it work.

One thing that helped me during all of the ports was to see the previously written code and understand how it was implemented. The style guide was also helpful in keeping the code clean and aligned with the other demos. At a certain point, I combined all of these along with improvement suggestions from my reviewers into a notes file.

Week 2

(This week will look more fruitful, I had good flow days this week and was starting to understand more about how the ports function).

Drawing Area demo port utilized multidimensional arrays, which in Vala are declared differently from other languages! You use arr_name[,] or arr_name[,,] where the commas represent the dimensions.

No function in GLib can convert degrees to radians. Hence, Lorenz suggested creating a function that could be used for the next GLib iteration and our demo.

Then I worked on numerous smaller ports, I’ll summarize their difficulty and things I learned from them in brief:

Frames, Label, and Menu Button demos were relatively easier to port and I was able to implement them quickly. The one thing that I was getting wrong up until here was not using explicit declarations for variables to make the code easier to comprehend.

Font Dialog demo utilizes async methods with await/yield calls to ensure that there is something returned always (required output/ error thrown). When implementing this demo in Vala I had compiler warnings stating implicit .begin() is deprecated

//Compiler throws an implicit begin warning
custom_button.clicked.connect (on_clicked);

//Fixed by explicitly connecting to the begin method
custom_button.clicked.connect (on_clicked.begin);

Network Monitor demo in particular took a lot of my brain cells, the whole code was rather easy to implement. The only thing that took most of my time was setting the value for the LevelBar, the value was to be fetched from NetworkMonitor, and the function that does this is NetworkMonitor.connectivity (which has a return type of enum). I did not realize that enum values can be cast into double and ended up creating a switch case iterator for the various connectivity types. The conditional loop was a better solution for the problem but Diego suggested that we cast it to double for consistency with other demos.

This week ended with a few more ports, namely Popovers, Power Profile Monitor, Spell Checker, Toggle Button, and Tooltip.

Here is your reward for reaching this far into the post

Week 3 (This may have taken longer than I anticipated)

The table of the ports? This is that table after Week 3

This week I worked on porting Progress Bar, Save File, Select Folder, and Spin Button(This demo was fun). All of the demos seemed less intimidating since they utilized similar functions and methods that I had already implemented in previous demos. Needless to say, it took extra time to port the last remaining demos because those were much longer and harder to keep track of.

Menu demo used container variables and one way to implement key and value pairs in Vala is to use HashTables (I had only heard about Hash tables being very useful before). It took me a lot of googling and trial and error to use a HashTable. Vala also supports syntactic sugar for set and get methods. This allows us to insert/lookup values to and from the table using keys and values as table indices

Eg:     content_type_params.insert ("charset", "UTF-8");
//Instead of calling insert method, you can insert into the value of
//charset index of the table
content_type_params["charset"] = "UTF-8";

//Similarly for lookup
var name = query.lookup ("name");
string name = query["name"];

HTTP Server demo uses HashTables, it also uses Soup.Server to deliver a local host server that can handle web requests.

Maps demo was an interesting one to port, the code in Python and Javascript utilized checking for (Not a Number) NaN characters but we used float.try_parse to check if the latitude and longitude entries are valid. It checks if the number is a valid float and if possible parses it to float.

The same week I ported Session Monitor and Inhibit. I had no understanding of the demo itself until Diego explained it to me very thoroughly.

File Monitor allows you to monitor file changes and see the changes you’ve made to the file in any text editor of your choice. The only issue with this port was the method to replace the contents of the file was inserting nonreadable text and the text editor was giving me issues when opening the file.

We fixed it by moving the handler to a separate async method call. It also took a huge chunk of time to port the Notification demo into Vala only to realize it couldn’t work. When using Vala in Workbench, the code and preview run as separate processes, and hence GApplication would not be registered properly and just gives a lot of other errors that I do not understand at the moment.

Another demo that used HashTables was Scrolled Window demo. The table was used to store Orientation and Scrollbars as key and value pairs.

As of writing this blog, Screencast, and Camera demos remain to be ported. These make use of the GStreamer library. There is already a draft PR for Screencast, the implementation requires further discussion with the reviewers.

These have been the updates from my side, thank you for reading. I would again like the thank Diego and Lorenz for all their help with reviewing and improving the ports.

It is time I move to the next part of my GSoC project and work on redesigning the Workbench Library. I will be back with more updates, stay tuned for those!

Until then

Understanding “Leading Questions” in Usability Research.

I’m in my internship's 3rd and 4th week, “conducting a series of short user research exercises using a mix of research methods”. Today, I want to talk about “leading questions,” a term that fascinated and confused me.

I heard of the the term “leading questions” during the 1st week of our internship when Allan Day, our Outreachy mentor for the May to August 2024 cohort, mentioned it briefly while discussing research design. I didn’t understand what it meant at the time. If you’re like me and wondering what it means, don’t worry — I got you.

Leading questions subtly prompt or encourage the respondent to answer in a particular way. These questions can influence the respondent’s answer by implying a preferred or expected response. In usability research, leading questions can bias the results and provide inaccurate insights into the user experience. Here’s an example:

Leading Question: “How much do you like our new drag-and-drop feature?”

Neutral Question: “What are your thoughts on our new drag-and-drop feature?”

The leading question assumes that the respondent likes the new feature, while the neutral question allows for any kind of feedback.

The benefits of not using leading questions are significant. Researchers can gather more accurate and genuine feedback by asking neutral, open-ended questions. This unbiased information helps in understanding the true opinions, needs, and pain points of users, leading to better design decisions and more effective improvements. It ensures that the data collected reflects the user’s real experience, rather than being skewed by the researcher’s assumptions.

You can read more about leading questions on this link.

On a more relaxed note, you can apply the concept of leading questions in your everyday life. For example, next time you cook dinner, don’t ask your guest, “How did you enjoy the meal?” Instead, ask, “What are your thoughts about the meal?” This way, you might get better insights into your cooking skills🍲.

June 14, 2024

Fedora Workstation development update – Artificial Intelligence edition

There are times when you feel your making no progress and there are other times when things feel like they are landing in quick succession. Luckily this definitely is the second when a lot of our long term efforts are finally coming over the finish line. As many of you probably know our priorities tend to be driven by a combination of what our RHEL Workstation customers need, what our hardware partners are doing and what is needed for Fedora Workstation to succeed. We also try to be good upstream partners and do patch reviews and participate where we can in working on upstream standards, especially those of course of concern to our RHEL Workstation and Server users. So when all those things align we are at our most productive and that seems to be what is happening now. Everything below is features in flight that will at the latest land in Fedora Workstation 41.

Artificial Intelligence

Granite LLM

IBM Granite LLM models usher in a new era of open source AI.

One of the areas of great importance to Red Hat currently is working on enabling our customers and users to take advantage of the advances in Artificial Intelligence. We do this in a lot of interesting ways like our recently announced work with IBM to release the high quality Granite AI models under terms that make them the most open major vendor AI models according to the Stanford Foundation Model Transparency Index , but not only are we releasing the full LLM source code, we are also creating a project to make modifying and teaching the LLM a lot easier through a project we call Instructlab. Instructlab is enabling almost anyone to quickly download a Granite LLM model and start teaching it specific things relevant to you or your organization. This put you in control of the AI and what it knows and can do as opposed to being demoted to a pure consumer.

And it is not just Granite, we are ensuring other other major AI projects will work with Fedora too, like Meta’s popular Llama LLM. And a big step for that is how Tom Rix has been working on bringing in AMD accelerated support (ROCm) for PyTorch to Fedora. PyTorch is an optimized tensor library for deep learning using GPUs and CPUs. The long term goal is that you should be able to just install PyTorch on Fedora and have it work hardware accelerated with any of the 3 major GPU vendors chipsets.

NVIDIA in Fedora
Fedora Workstation
So the clear market leader at the moment for powering AI workloads in NVIDIA so I am also happy to let you know about two updates we are working on that will make you life better on Fedora when using NVIDIA GPUs, be that for graphics or for compute or Artificial Intelligence. So for the longest time we have had easy install of the NVIDIA driver through GNOME Software in Fedora Workstation, unfortunately this setup never dealt with what is now the default usecase, which is using it with a system that has secure boot enabled. So the driver install was dropped from GNOME Software in our most recent release as the only way for people to get it working was through using mokutils on the command line, but the UI didn’t tell you that. Well we of course realize that sending people back to the command line to get this driver installed is highly unfortunate so Milan Crha has been working together with Alan Day and Jakub Steiner to come up with a streamlined user experience in GNOME Software to let you install the binary NVIDIA driver and provide you with an integrated graphical user interface help to sign the kernel module for use with secure boot. This is a bit different than what we for instance are doing in RHEL, where we are working with NVIDIA to provide pre-signed kernel modules, but that is a lot harder to do in Fedora due to the rapidly updating kernel versions and which most Fedora users appreciate as a big plus. So instead what we are for opting in Fedora is as I said to make it simple for you to self-sign the kernel module for use with secure boot. We are currently looking at when we can make this feature available, but no later than Fedora Workstation 41 for sure.

Toolbx getting top notch NVIDIA integration


Container Toolbx enables developers quick and easy access to their favorite development platforms

Toolbx, our incredible developer focused containers tool, is going from strength to strength these days with the rewrite from the old shell scripts to Go starting to pay dividends. The next major feature that we are closing in on is full NVIDIA driver support with Toolbx. As most of you know Toolbx is our developer container solution which makes it super simple to set up development containers with specific versions of Fedora or RHEL or many other distributions. Debarshi Ray has been working on implementing support for the official NVIDIA container device interface module which should enable us to provide full NVIDIA and CUDA support for Toolbx containers. This should provide reliable NVIDIA driver support going forward and Debarshi is currently testing various AI related container images to ensure they run smoothly on the new setup.

We are also hoping the packaging fixes to subscription manager will land soon as that will make using RHEL containers on Fedora a lot smoother. While this feature basically already works as outlined here we do hope to make it even more streamlined going forward.

Open Source NVIDIA support
Of course being Red Hat we haven’t forgotten about open source here, you probably heard about Nova our new Rust based upstream kernel driver for NVIDIA hardware which will provided optimized support for the hardware supported by NVIDIAs firmware (basically all newer ones) and accelerate Vulkan through the NVK module and provide OpenGL through Zink. That effort is still quite early days, but there is some really cool developments happening around Nova that I am not at liberty to share yet, but I hope to be able to talk about those soon.

High Dynamic Range (HDR)
Jonas Ådahl after completing the remote access work for GNOME under Wayland has moved his focus to help land the HDR support in mutter and GNOME Shell. He recently finished rebasing his HDR patches onto a wip merge request from
Georges Stavracas which ported gnome-shell to using paint nodes,

So the HDR enablement in mutter and GNOME shell is now a set of 3 patches.

With this the work is mostly done, what is left is avoiding over exposure of the cursor, and inhibiting direct scanout.

We also hope to help finalize the upstream Wayland specs soon so that everyone can implement this and know the protocols are stable and final.

DRM leasing – VR Headsets
VR Googles
The most common usecase for DRM leasing is VR headsets, but it is also a useful feature for things like video walls. José Expósito is working on finalizing a patch for it using the Wayland protocol adopted by KDE and others. We where somewhat hesitant to go down this route as we felt a portal would have been a better approach, especially as a lot of our experienced X.org developers are worried that Wayland is in the process of replicating one of the core issues with X through the unmanageable plethora of Wayland protocols that is being pushed. That said, the DRM leasing stuff was not a hill worth dying on here, getting this feature out to our users in a way they could quickly use was more critical, so DRM leasing will land soon through this merge request.

Explicit sync
Another effort that we have put a lot of effort into together with our colleagues at NVIDIA is landing support for what is called explicit sync into the Linux kernel and the graphics drivers.The linux graphics stack was up to this point using something called implicit sync, but the NVIDIA drivers did not work well with that and thus people where experiencing ‘blinking’ applications under Wayland. So we worked with NVIDIA and have landed the basic support in the kernel and in GNOME and thus once the 555 release of the NVIDIA driver is out we hope the ‘blinking’ issues are fully resolved for your display. There has been some online discussion about potential performance gains from this change too, across all graphics drivers, but the reality of this is somewhat uncertain or at least it is still unclear if there will be real world measurable gains from adding explicit sync. I heard knowledgeable people argue both sides with some saying there should be visible performance gains while others say the potential gains will be so specific that unless you write a test to benchmark it explicitly you will not be able to detect a difference. But what is beyond doubt is that this will make using the NVIDIA stack with Wayland a lot better a that is a worthwhile goal in itself. The one item we are still working on is integrating the PipeWire support for explicit sync into our stack, because without it you might have the same flickering issues with PipeWire streams on top of the NVIDIA driver that you have up to now seen on your screen. So for instance if you are using PipeWire for screen capture it might look fine on screen with the fixes already merged, but the captured video has flickering. Wim Taymans landed some initial support in PipeWire already so now Michel Dänzer is working on implementing the needed bits for PipeWire in mutter. At the same time Wim is working on ensuring we have a testing client available to verify the compositor support. Once everything has landed in mutter and we been able to verify that it works with the sample client we will need to add support to client applications interacting with PipeWire, like Firefox, Chrome, OBS Studio and GNOME-remote-desktop.

#152 Bottom Sheets

Update on what happened across the GNOME project in the week from June 07 to June 14.

GNOME Core Apps and Libraries


Building blocks for modern GNOME apps using GTK4.

Alice (she/her) announces

AdwBottomSheet is now public, allowing apps to use bottom sheets outside dialogs. It also has an optional bottom bar, which may be useful for music player apps.

GNOME Incubating Apps

Pablo Correa Gomez announces

This week Papers, the Incubator app for viewing documents, had its first release published on Flathub! Now you can download a stable version instead of using GNOME nightly. We are hoping to get more testing and feedback from the community!

In the meanwhile, development continues at a high pace! Qiu Wenbo has continued porting many widgets to libadwaita, UI templates, and Rust, I have focused on cleanups, and as part of GSoC Markus Göllnitz has continued improving the UI! The top headerbar is now split in two, and search happens over the sidebar. Not only allows this to fit the UI in a phone size, but also provides better modularity, making the application more maintainable.

GNOME Circle Apps and Libraries


Travel with all your train information in one place.

schmiddi says

Railway version 2.6.0 was now published. This release refactors a lot of the backend of Railway, such that we can now support many more providers. As a start, Railway now supports SBB and the Transitous project. Adding new providers should be an easy task if one is proficient with the Rust programming language and the provider has an easy API one can use. To help anybody to contribute their favourite provider, in the case it is not yet implemented, we have extensive documentation on how to write such an implementation. In case you want to help out, feel free to write us a message. Even though this was the biggest change with this release, it was not the only one. We improved the user experience in some parts of the application, for example you will now be informed about the option to delete old journeys to clean out these bookmarks automatically. We also made the application more accessible, with support for screen readers for searching for stations.

Third Party Projects

DaKnig says

DewDuct v0.2.3 is released! currently working on behind the scenes things, so not many exciting news besides some bugs squashed and some performance improved ~

Please, if you have any ideas, contact me on Matrix! (Daknig on Matrix dot org). Even if you have no prior experience in GTK and are just meddling in Rust, I promise to help!

The situation with invidious being blocked is going to affect DewDuct, the future is uncertain; But, for now, enjoy the new released and see your bugs squashed!

The release would be available on alpine shortly after this post goes live!

Bilal Elmoussaoui says

I have released gir-parser, a complete parser of the GObject Introspection GIR files written in Rust. It can be used as a base for writing a documentation/bindings generator.

GNOME Websites

Emmanuele Bassi says

GNOME’s Discourse web forum now publishes topics for various blogs using their RSS feed, like:

  • the Foundation’s news blog
  • the GTK developers blog
  • the GNOME Shell developers blog
  • This Week in GNOME (hi!)

and more will follow in the future. You can use Discourse for comments, feedback, and discussions.

GNOME Foundation

Michael Downey announces

Along with our friends at KDE e.V. and Eclipse Foundation, the GNOME Foundation was recently invited to become an Associate Member of the new Matrix.org Foundation to help provide feedback on making the platform more useful for communities like GNOME to collaborate on free software development.

Strengthening partnerships between free software communities like ours is an important aspect of project sustainability. We remain grateful to the Matrix.org Foundation for providing the infrastructure used for GNOME’s rooms and Foundation member accounts.

As part of their recent Governing Board launch, I’m pleased to share that Cleo Menezes Jr. has been appointed to be GNOME’s first delegate to this group. Cleo will help advocate for GNOME in using and helping others use Matrix, so if you have any feedback or questions, get in touch.

Caroline Henriksen announces

The call for GUADEC 2024 BoFs and Workshops is open for one more day. If you would like to host an in-person or remote session make sure to submit your proposal by tomorrow (June 15): https://foundation.gnome.org/2024/06/04/guadec-2024-call-for-bofs-and-workshops/

Quick reminder to also register for GUADEC! This year’s conference runs from July 19-24, let us know if you’re attending in person or remotely by signing up here: https://events.gnome.org/event/209/registrations/

For anyone attending in person in Denver, we’re planning a number of social events so make sure to check the website for more details. We’ll be adding details for a pre-registration party on July 19 and options for a social activity on July 24 soon, but you can register for our July 22 family-friendly baseball game (Colorado Rockies vs Boston Red Sox) right now: https://events.gnome.org/event/209/page/331-colorado-rockies-baseball-game

That’s all for this week!

See you next week, and be sure to stop by #thisweek:gnome.org with updates on your own projects!

June 13, 2024

Sketch Friday

I’ve been posting a few sketches on my mastodon every Friday. They are mostly sketches of application icon design process, but not always. Follow, like, subscribe!

04e5ae648d8b3640 Exhibit2 05521b4858a9cdef Exhibit 0934a02f1c915ef7 f340603a0cd5eb83 0f02657ab2fb4012 Gameeky 10 1e6abb0c31ee6066 Gameeky 11 286a44fb410d5ad3 Gameeky 8 2f6c03bd10824d1d Gimp 2 48d49e6ce2bcebb5 Gimp 5af3244c6aef1539 Handbook_And_Developers Afternoon 3 Inkscape Afternoon Key_Rack 1 AI Laptop 1 Alpaca 1 2 Laptop3 Alpaca 2 Laptop Alpaca 4 Luminance 1 Alpaca Memorize 1 Aurea 3 Memorize 2 Aurea Memorize Captive_Portal4 Mypaint Captive_Portal5 Nvidia_Toolbx cbad883c19680ae2 Office_Runner 1 cd2b1f4788bd40c9 Office_Runner Collector Orca 2 Convolution 2 Orca Convolution 3 Papers 4 Convolution Papers 7 d6d20716bd43b122 Plots 2 d711da1c0aeec75f Power_Modes dabc00e72dc94dca Seabird 2 ddff8a8e07260602 Seabird Dew_Duct Valuta 1 Valuta e0d5efac768fe1aa Videos 2 Exhibit 1 Videos 3 Exhibit 2

Linter breaking change: restricting automatic merge

Starting next week, June 17th, the linter will no longer allow enabling automatic merge for pull requests created by flatpak-external-data-checker, unless the app uses an extra-data source or has been added to the exceptions list.

The verified apps utilizing automerge-flathubbot-prs before May 28th have been grandfathered and no explicit action is required from the maintainers. If your app does not meet these criteria, you can still request an exception by creating a pull request to the flatpak-builder-lint repository. Exception requests will be judged on a case-by-case basis on providing valid reasons.

The automerge-flathubbot-prs feature has been introduced back in 2019 to reduce maintenance overhead of applications dependent on non-redistributable data. If an extra-data source used by the app disappears because of an update, the automation would ensure that it is still possible to install the app, without requiring manual intervention from the maintainers.

Over time, the feature has started to be misused as a general purpose automation for publishing updates without proper testing. This has led to a number of issues where apps became broken overnight, which could have been easily prevented if the update was tested before merging.

June 12, 2024

SSH agent extensions as an arbitrary RPC mechanism

A while back, I wrote about using the SSH agent protocol to satisfy WebAuthn requests. The main problem with this approach is that it required starting the SSH agent with a special argument and also involved being a little too friendly with the implementation - things worked because I could provide an arbitrary public key and the implementation never validated that, but it would be legitimate for it to start doing so and then break everything. And it also only worked for keys stored on tokens that ssh supports - there was no way to extend this to other keystores on the client (such as the Secure Enclave on Macs, or TPM-backed keys on PCs). I wanted a better solution.

It turns out that it was far easier than I expected. The ssh agent protocol is documented here, and the interesting part is the extension support extension mechanism. Basically, you can declare an extension and then just tunnel whatever you want over it. As before, my goto was the go ssh agent package which conveniently implements both the client and server side of this. Implementing the local agent is trivial - look up SSH_AUTH_SOCK, connect to it, create a new agent client that can communicate with that by calling NewClient, and then implement the ExtendedAgent interface, create a new socket, and call ServeAgent against that. Most of the ExtendedAgent functions should simply call through to the original agent, with the exception of Extension(). Just add a case statement against extensionType, define some reasonably namespaced extension, and you're done.

Now you need to use this agent. You probably don't want to use this for arbitrary hosts (agent forwarding should only be enabled for remote systems you trust, not arbitrary machines you connect to - if you enabled agent forwarding for github and github got compromised, github would be able to use any private keys loaded into your agent, and you probably don't want that). So the right approach is to add a Host entry to the ssh config with a ForwardAgent stanza pointing at the socket you created in your new agent. This way the configured subset of remote hosts will automatically talk to this new custom agent, while forwarding for anything else will still be at the user's discretion.

For the remote end things are even easier. Look up SSH_AUTH_SOCK and call NewClient as before, and then simply call client.Extension(). Whatever you stick in the contents argument will simply end up being received at the client end. You now have a communication channel between a the remote system and the local client, and what you do with that is up to you. I'm using it to allow a remote system to obtain auth tokens from Okta and forward WebAuthn challenges that can either be satisfied via a local WebAuthn token or by passing the query off to Mac TouchID, but there's fundamentally no constraints whatsoever on what can be done here.

(If you want to do this on Windows and still have everything work with existing clients you'll need to take this into account - Windows didn't really do Unix sockets until recently so everything there is awful)

comment count unavailable comments

June 11, 2024

Announcing systemd v256

Yesterday evening we released systemd v256 into the wild. While other projects, such as Firefox are just about to leave the 7bit world and enter 8bit territory, we already entered 9bit version territory! For details about the release, see our announcement mail.

In the weeks leading up to this release I have posted a series of serieses of posts to Mastodon about key new features in this release. Mastodon has its goods and its bads. Among the latter is probably that it isn't that great for posting listings of serieses of posts. Hence let me provide you with a list of the relevant first post in the series of posts here:

I intend to do a similar series of serieses of posts for the next systemd release (v257), hence if you haven't left tech Twitter for Mastodon yet, now is the opportunity.

And while I have you: note that the All Systems Go 2024 Conference (Berlin) Call for Papers ends 😲 THIS WEEK 🤯! Hence, HURRY, and get your submissions in now, for the best low-level Linux userspace conference around!

11 Jun 2024


To celebrate that RealityKit's is coming to MacOS, iOS and iPadOS and is no longer limited to VisionOS, I am releasing SwiftNavigation for RealityKit.

Last year, as I was building a game for VisionPro, I wanted the 3D characters I placed in the world to navigate the world, go from one point to another, avoid obstacles and have those 3D characters avoid each other.

Almost every game engine in the world uses the C++ library RecastNavigation library to do this - Unity, Unreal and Godot all use it.

SwiftNavigation was born: Both a Swift wrapper to the underlying C++ library which leverages extensively Swift's C++ interoperability capabilities and it directly integrates into the RealityKit entity system.

This library is magical, you create a navigation mesh from the world that you capture and then you can query it for paths to navigate from one point to another or you can create a crowd controller that will automatically move your objects.

Until I have the time to write full tutorials, your best bet is to look at the example project that uses it.

GNOME 46 and Beyond

With GNOME 46.2 released, it seems like a good time to write a post about goings on in GNOME Online Accounts and other STF-funded initiatives. There's a lot to be excited about this cycle and most of it is leading to more improvements in the near future.

# GNOME Online Accounts

A lot happened in GNOME 46 for GNOME Online Accounts, including two new providers, a port to GTK4 and Adwaita, authentication in the desktop browser, and a large refactoring towards contemporary platform conventions.

The new WebDAV and Microsoft 365 providers contrast quite a bit, although both made progress in the general direction we want to move. The existing Nexcloud provider was a good starting point for WebDAV, but support for more implementations and auto-discovery were important goals for our push towards open protocols and local-first principles.

# WebDAV

The WebDAV provider seemed like it would be fairly straightforward, however feedback from the community has shown that several popular services like Fastmail and mailbox.org offer support for features like custom domain names and app passwords restricted by content type. These are great features, but not supported by a naive implementation of standard service discovery.

The large refactoring in GNOME 46 de-duplicated a lot of code and is much easier to use, but a lot of the account setup process is still tightly coupled to the user interface. The new work being done to support more service configurations and improve the user experience is separate from the provider code, which has already led to the easy integration of some nice features:

In the video above, you can see the implementation of Mail Autoconfig at work detecting settings for Fastmail from the email address, in the otherwise unchanged Email setup dialog. I'd like to thank Tyler and the rest of the development team at Fastmail for extending me an account for additional testing this cycle. By design, Mail Autoconfig doesn't need authentication, but this account was very helpful while improving support for content-restricted app passwords.

These app passwords are especially relevant to WebDAV, which received a few adjustments to adopt an internal API compatible with the Mail Autoconfig implementation. While the WebDAV setup dialog hasn't landed the same UI feedback improvements yet, there is a work-in-progress that does:

In this video, you can see an early prototype for a goal of a lot of this work. Thanks to the research and work of Éloi Rivard we have an excellent whiteboard for Generic Service Providers, detailing a large amount of the subject matter. The immediate goal then is to offer an account type that's easy to set up, supports the common set of services (mail, calendar, contacts and files) and adapts to the available services using open protocols and standards.

We still have longer-term changes planned to support a sandbox-friendly ecosystem, but it's not yet clear what form GNOME Online Accounts will take or how applications will interact with it. For this reason, all the new code supporting Mail Autoconfig and WebDAV was written for potential reuse later, without investing in becoming yet another Accounts SSO.

# Microsoft 365

Much of the recent work on GNOME Online Accounts was funded by the Sovereign Tech Fund, while the Microsoft 365 provider is the work of Jan-Michael Brummer. The initial support includes access to OneDrive with Files and GVfs, with support for email, contacts and calendar planned for the near future. While our focus remains on open protocols and local-first principles, it's still a goal to support services that the people use in their work and provide benefit to the community.

Something interesting the project gained from Jan's work is the first OAuth provider with support for user-provided client IDs. Currently, every distributor and fork of GNOME Online Accounts has been using the GNOME Foundation's client IDs for OAuth providers. This can be problematic depending on the terms of service and restrictive for those using enterprise or organizational accounts.

A screenshot of the Microsoft 365 setup dialog in GNOME 46.2, with confusingly optional entry fields

Unfortunately, the first iterations of the setup dialog did not result in a good user experience. Microsoft's services come with their own concepts and terminology, which really resulted in a lack of clear direction in the design of the interface during an already busy release cycle. The tight coupling between logic and user interface did not help here either, as evidenced by the double-modal:

A screenshot of the Microsoft 365 setup dialog in GNOME 46.2, with a "Sign In with your browser" dialog stacked on top

The amount of feedback and issues reported has been the most help here, as we learn how Microsoft 365 is being used by the open-source community in both personal and work-related environments. Support for more services like email, calendar and contacts are planned, and hopefully some better support for organizational accounts.

# Orca and Spiel

Something I am thrilled to have the opportunity to take part in is Spiel, a new speech synthesis service by Eitan Isaacson that's a bit reminiscent of MPRIS. New speech providers can be easily written in C, Rust or any other language binding and libspiel will aggregate them for the client.

An interesting difference with Speech Dispatcher is that while the speech provider takes responsibility for speech synthesis, the client application takes responsibility for the audio output. Internally, the speech provider returns a file descriptor over D-Bus and GStreamer is used to output the audio on the client side.

While Spiel does have some exciting possibilities outside of screen readers, including new synthesizers like Piper, you may be surprised to find the speech rate that many users operate a screen reader at. Léonie Watson has an excellent blog post titled Notes on synthetic speech, with plenty of audio clips and insights into how screen readers are used by real people.

I was fortunate enough to have the opportunity to integrate Spiel into Orca, which was a great learning experience and re-sparked my interest in accessibility in general. Something else to watch out for is Matt Campbell's Newton project, bringing a modern accessibility stack to Wayland.

# Acknowledgements

I'd like to again thank the Sovereign Tech Fund for investing in the GNOME project. Their targeted funding of infrastructure and accessibility has empowered a lot of overdue improvements for open source and the GNOME platform.

I'd also like to thank the development team at Fastmail, who upon request graciously granted us an extended account, to continue testing support for their service. The support staff at mailbox.org also extended a trial period as a show of good faith. It's been really encouraging to have these companies show support for the community, thank you!

As always, GNOME's community of contributors and users have been the most help, with diligent reporting, code reviews and advice. There are so many things happening in open source, I really wouldn't be able to keep up without all your help.

June 10, 2024

2024-06-10 Monday

  • Mail chew; packed for OW2con; 1:1s with Andras and Miklos, M. drove me to the station, train(s) to Paris, caught up with admin.
  • Eventually got to the hotel; met up with Meven for dinner - and back to work.

June 09, 2024

2024-06-09 Sunday

  • Up; All Saints, played Guitar with Mary and iSing; home for pizza lunch; Hopper wedding - played with Cedric and Sian & Mary - reception afterwards.
  • Home to rest; finished All the light you cannot see or somesuch - good; then also About Time - unsuitable but well meant.

June 07, 2024

CSS Happenings

This cycle GTK got a lot of updates to its CSS engine.

I started this work as part of the Sovereign Tech Fund initiative, and later on Matthias Clasen joined in and we ended up splitting the work on colors.

Let’s go through the changes, as well as how they affect GTK, libadwaita and apps.


The most notable addition is CSS variables, more correctly known as custom properties.

Since before GTK switched to CSS for styles, it has had named colors, a non-standard addition providing a similar functionality. You could define a color, then refer to it by name. Unfortunately, they had big limitations. First, they are global. You can only define colors for the whole stylesheet, and if you want to override them for a single widget subtree – you’re out of luck. Second, they were obviously only for colors.

The only option to have them local to a widget was to use gtk_style_context_add_provider() on a GtkStyleContext obtained via gtk_widget_get_style_context. However, it had an even bigger problem: being local to a widget, it didn’t propagate to children, which made it practically useless. Even for widgets that seemingly don’t have children: for example, if you add a provider to a GtkEntry, it won’t affect its text, or the icons, or the progress bar – they are all separate widgets within the entry. So, it shouldn’t be a big surprise that this API is deprecated.

Variables, meanwhile, don’t have any of these limitations. They can be defined anywhere, propagate to children, and they can be anything – colors, numbers, dimensions, etc. For example, we can override them for a specific widget as follows:

:root {
  --some-color: red;

my-widget {
  --some-color: green;

After defining, they can be accessed with the var() function:

my-widget {
  color: var(--some-color);

This function also allows to specify a fallback in case a variable doesn’t exist, as follows:

my-widget {
  color: var(--some-color, var(--some-other-color, red));

Here it will try, in order, --some-color, then --some-other-color, and if neither exists, red.

The standard place to declare global variables is the :root selector, and so it’s now supported too. While GTK root widgets usually have the window selector, that’s not always the case. For example, GtkCheckButton within a GtkTreeView are their own toplevels and targeting window would not include them. While tree view is deprecated and hopefully on its way out, we have to support it anyway for now, and who knows what other root widgets appear in future, and having :root solves it all nicely.

Variables can even be animated, though that’s not particularly useful: since they can be anything and you may potentially be animating red into 2px, the only way to interpolate them is to have a jump from the initial value to final value at 50%. Either way, the spec allows that and we implement it. You can still use them within another property’s value and animate that property instead – that will work as expected.

There are some things we don’t support at the moment, like the @property at-rule. It allows to declare variable types, optionally prevent inheriting, and specify the default value. Having a type not only provides type checking (and hence more informative error messages), but also allows to actually interpolate variables in animations. See, if a variable can be anything, we can’t interpolate it other than with a jump in the middle. But if we can guarantee it’s a color, or a dimension, or a number, or whatever, at every keyframe, then we can. But, while that would be neat to have, it’s really niche compared to having variables themselves, and so not very important.

Another thing is that it’s not possible to use variables within named colors, like this:

@define-color my_color var(--something); /* this is an error */

Since named colors will be going away in future, that’s not a big deal, but it is worth mentioning anyway. The other way around does work though:

@define-color something red;

:root {
  --my-color: @something; /* this is perfectly fine */

(and that’s fairly important, as it allows us to switch to variables without breaking backwards compatibility)


Next, colors. A lot of features from CSS Color Module Level 4 and Level 5 were implemented as well.

Modern syntax

In the past, CSS has used the following syntax for defining colors:

rgb(255, 0, 0)
rgba(255, 0, 0, 0.5)
hsl(0, 100%, 50%)
hsla(0, 100%, 50%, 0.5)

That’s still supported, but modern CSS also has a simpler and more flexible syntax:

rgb(255 0 0)
rgb(255 0 0 / 50%)
hsl(0 100 50)
hsl(0 100 50 / 50%)

It allows to freely mix percentages and numbers, and makes alpha an optional parameter separated by solidus instead of having separate functions. And now GTK supports it too.

Modern syntax also supports specifying missing components, for example: hsl(none 100% 50%). In most situations they behave same as 0, but they make a difference for interpolation, so we’ll talk about that in more details later.

Additionally, it supports specifying hue in hsl() as an angle instead of a number (meaning that it’s possible to use units like turn instead of degrees), as well as calc() anywhere within these functions:

hsl(calc(0.5turn - 10deg) 100% 50% / calc(1 / 2))

More color spaces

GTK also supports a bunch more color spaces now, all using the modern syntax:

Color space CSS
Linear sRGB color(srgb-linear 1 0 0)
HWB hwb(0deg 0 0)
Oklab oklab(62.8% 0.22 0.13)
Oklch oklch(62.8% 0.25 29)

    I won’t be describing the color spaces in detail, but that information can be easily found online. For example, Oklab and Oklch are very well described in their creator’s blog post.

    color() also supports sRGB, but it works same as rgb(), except the channels have 0-1 range instead of 0-255.

    color() in the spec supports a lot more color spaces, for example Display P3, but since we don’t have HDR support in GTK just yet, supporting them wouldn’t be of much use at the moment, so that’s omitted. Also omitted are Lab, LCh and various XYZ color spaces for now. Oklab/Oklch work better than Lab/LCh for UI colors anyway, and XYZ is fairly niche and not widely used in this context.

    However, just defining colors in different color spaces isn’t that interesting to me. What’s more interesting is deriving new colors from from existing ones in those color spaces, so let’s look at that.

    Color mixing

    First, we have support for the color-mix() function. While GTK has had a non-standard mix() function for more than a decade, color-mix() is not only standard CSS, but also a whole lot more flexible. Most important is the fact it allows to mix colors in different color spaces instead of just sRGB – all of the ones mentioned above:

    color-mix(in oklch, red, green)

    For HSL, HWB and Oklch, it’s possible to specify the hue interpolation mode too – for example, color-mix(in hsl longer hue, red, green).

    color-mix() also allows more sophisticated mixing via missing components. They allow some channels to be taken from one of the colors without taking the other one into account at all. For example, the following mix:

    color-mix(in srgb, rgb(100% none 100%), rgb(none 50% 0))

    takes the red channel from the first color, the green channel from the second color, and mixes the blue channel from both colors, resulting in the following color: color(srgb 1 0.5 0.5).

    For comparison, the same mix but with none replaced by 0:

    color-mix(in srgb, rgb(100% 0 100%), rgb(0 50% 0))

    mixes every channel and produces color(srgb 0.5 0.25 0.5).

    While mix() specifies a single fraction for the mix, color-mix() specifies two percentages. Usually they are normalized so that they add up to 100%, but if their sum is lower than that, it’s used as an alpha multiplier, allowing to add transparency to the mix:

    color-mix(in srgb, red 30%, blue 20%)
    /* color(srgb 0.6 0 0.4 / 0.5) */

    Percentages are optional though. When one is omitted, it’s assumed to be the other one subtracted from 100%. When both are omitted, they are assumed to be 50%/50%.

    Relative colors

    GTK now also supports relative colors. Unlike mixing, these take one color and change its individual channels. For example, we can create a complementary color by inverting the hue:

    hsl(from var(--some-color) calc(h + 0.5turn) s l)

    Change a color’s lightness to a given value:

    oklab(from var(--some-color) 0.9 a b)

    Or add transparency to a color, like the SASS transparentize() function:

    rgb(from var(--some-color) r g b / calc(alpha - 25%))

    Combined with calc() and variables, this is a very flexible system, and I’m really curious to see how it will get used in future.

    Math functions

    There’s also support for a lot of math functions:

    • min(), max(), clamp()
    • round()
    • rem()
    • mod()
    • sin(), cos(), tan(), asin(), acos(), atan(), atan2()
    • pow(), sqrt(), hypot(), log(), exp()
    • abs(), sign()
    • e, pi, infinity, NaN

    They can also be used in calc(), of course. I already found an interesting use case for two of them in libadwaita.

    Misc changes

    The opacity property can now accept percentages in addition to numbers. This wouldn’t matter much, but it means it can accept the same values as color-mix().

    Now let’s look at other changes all of this allowed.

    GTK deprecations

    GTK has a bunch of non-standard additions to CSS, related to colors: most notably, @define-color and named colors, but also the alpha(), mix(), shade(), lighter() and darker() functions. They allow to manipulate colors. Some are more useful than others, but, for example, alpha() is used extensively in libadwaita and modern GNOME apps – especially in combination with currentColor. For example, libadwaita buttons have the following background color: alpha(currentColor, 0.1); and can work with both light and dark background – they just follow the text color.

    As useful as they are, CSS now has standard ways to replace every single one of them, and apps are encouraged to do so.

    Named colors

    @define-color and named colors can be replaced with variables. For example, this snippet:

    @define-color my_color red;
    my-widget {
      color: @my_color;


    :root {
      --my-color: red;
    my-widget {
      color: var(--my-color);


    This is straightforward. color-mix() works exactly same when using the sRGB color space.

    /* mix(red, blue, .3) */
    color-mix(in srgb, red 30%, blue)


    There are multiple ways to replace it. Both color-mix() and relative colors will do the job:

    /* alpha(currentColor, 0.15); */
    color-mix(in srgb, currentColor 15%, transparent)
    rgb(from currentColor r g b / calc(alpha * 0.15))

    Note that only the latter works for factors larger than 1.

    alpha() is also often used with hardcoded colors, usually black. In that case just defining the color as is is sufficient:

    /* alpha(black, .8) */
    rgb(0 0 0 / 80%)


    Shading is less obvious. One might assume that it would work same as mixing with black or white color, but… not quite. It was converting the colors to HSL, multiplying lightness and saturation, and converting back to sRGB. As such, mixing wouldn’t exactly work here, it will produce close but subtly different results, even when done in the HSL color space. For some color/factor combinations it would be same, but other times it will be different.

    Relative colors, meanwhile, allow to manipulate each channel separately, and together with calc() we can do exactly same thing:

    /* shade(red, 1.1) */
    hsl(from red h calc(s * 1.1) calc(l * 1.1))

    This is a lot more verbose, but it produces the same result as shade() for any color and factor. Of course, one could go further and use color spaces like Oklch or Oklab instead, and have more consistent results due to their perceptual nature. More on that later.

    lighter() and darker()

    Well, these are simple. They are just shade() with hardcoded factor parameter: 1.3 for lighter() and 0.7 for darker(). As such, they are replaced the same way:

    /* lighter(red) */
    hsl(from red h calc(s * 1.3) calc(l * 1.3))
    /* darker(red) */
    hsl(from red h calc(s * 0.7) calc(l * 0.7))

    Libadwaita changes

    This has allowed to clean up a lot of things in libadwaita styles too.

    Named colors?

    First of all, all of the existing named colors are available as variables too now. For backwards compatibility reasons their defaut values reference the old colors, for example:

    :root {
      --window-bg-color: @window_bg_color;
      --window-fg-color: @window_fg_color;

    They are named the same way as for the old colors, but with dashes in the names instead of underscores. One exception is that @borders became --border-color instead, for consistency with other colors.

    However, being variables they can still be overridden per widget, have fallbacks and so on.

    NOTE: since they reference named colors, using these variables will produce deprecation warnings with GTK_DEBUG=css. This is a known issue, but there isn’t much that can be done here, other than breaking compatibility for all existing apps with custom styles.

    Also, overriding these variables won’t affect styles that use the old named colors directly. This isn’t a big issue if you’re porting your app (because you can replace both definitions and mentions at once), but may be a problem with libraries like libpanel which provide their own styles and use a lot of named colors. Once those libraries are ported though, it will work fine for both apps that have and haven’t been updated.

    All of the available CSS variables are documented on their page, just like the old named colors. If you’re using libadwaita 1.5 or below, the old docs are still where they were.

    It should be noted that compability colors like @theme_bg_color don’t have equivalent variables. Those colors only exist for compatibility, and apps using libadwaita shouldn’t be using them in the first place – specifically that color can be replaced by --window-bg-color, and so on. This can be a problem for libraries like WebKitGTK, however, so maybe there should be an agreed upon set of variables too. For now though, named colors still exist and won’t go away until GTK5, but this is something that needs be figured out at some point.

    New variables

    There are a few additions as well:

    • The opacity used for borders is also available separately now, as --border-opacity.
    • The opacities used for the .dim-label style class and disabled widgets are available as well, as --dim-opacity and --disabled-opacity respectively.
    • --window-radius refers to the window’s current corner radius. Normally it’s 12px, but it becomes 0 when the window is maximized, tiled and so on. It can be used for things like rounding focus rings near window corners only for floating windows, instead of using a long and unwieldy selector like this:

      window:not(.maximized):not(.tiled):not(.tiled-left):not(.tiled-right):not(.tiled-top):not(.tiled-bottom):not(.fullscreen):not(.solid-csd) my-widget {
        /* yikes */

    Style changes

    There were a few things that we wanted to do for a while, but that needed variables to be feasible. Now they are feasible, and are implemented.

    Screenshot of a toolbar with .osd style class. It's dark, with light text. It has a GtkScale in it, which is light grey instead of blue.

    For example, the .osd style overrides accent color to be light grey. Previously this was done with separate overrides for every single widget that uses accent, and in some cases blue accents sneaked through anyway. It also didn’t work with custom widgets defined in apps, unless they special cased it themselves. Now it just overrides the accent color variables and is both much simpler and actually consistent.

    Screenshot of a destructive button saying "Destructive Button". It's focused, and the focus ring is red.

    Destructive buttons previously had blue focus rings, and now they are red, matching the buttons themselves. Moreover, apps can easily get custom-colored widgets like this themselves, with matching focus rings.

    Since previously we couldn’t override accent color per-widget, the way to recolor buttons (as well as checks, switches etc) was to just set background-color and color properties manually. It worked, but obviously didn’t affect focus rings, and focus rings are complicated, so doing it manually wouldn’t be feasible. They have a very specific color with a specific opacity, a different opacity for the high contrast mode, and the actual selector changes a lot between widgets. In case of buttons it’s button:focus:focus-visible, for entries it’s entry:focus-within and so on. Not very good, so we didn’t encourage apps to change focus rings, and didn’t change them on destructive buttons either.

    But now that we have variables, people can just override the accent color, and focus rings will follow the suit. For example, to make a green button, an app can just apply .suggested-action and override accent on it to green:

    Screenshot of a green pill button saying "Very Green Button" on top of a light background. It's focused and the focus ring is green.Screenshot of a green pill button saying "Very Green Button" on top of a dark background. It's focused and the focus ring is green.

    So, for example, Calculator can now make its big orange result button orange and have matching focus ring on it without changing accent color in the whole app.

    Because of that, the .opaque style class has been deprecated. Instead, apps are encouraged to use .suggested-action like above.

    Meanwhile, GtkEntry with .error, .warning and .success style classes have had red focus rings, as an exception. Later, AdwEntryRow gained the same styles, but that was messy overall. But now these style classes just set accent color in addition to text color, so these styles aren’t special cases anymore – they will work with any widget.

    Deriving accent colors

    Since 1.0, libadwaita has had two separate accent colors: --accent-bg-color and --accent-color. The former is suitable for use as a background on widgets like buttons, checks and switches, but usually has too low contrast to be used as a text color. The latter has a higher contrast, suitable for use as text, but it doesn’t work well as a background.

    That’s a bit confusing, and I’ve seen a lot of apps misusing them. Some apps set a custom accent color and just set them to the same value, so they don’t have enough contrast. Some apps mix up the colors and use the wrong one. And so on.

    It would be really nice if we could generate one from the other one. Previously this was firmly in the realm of pipe dreams, but now that we have relative colors, it’s a lot more feasible.

    For example, the following functions produce consistently good colors for light and dark styles respectively:

    /* light style */
    --accent-color: oklab(from var(--accent-bg-color) min(l, 0.5) a b);
    /* dark style */
    --accent-color: oklab(from var(--accent-bg-color) max(l, 0.85) a b);

    Here are some examples, for both light and dark style:

    Screenshot of a window with its left half being light and right half being dark. Each half has 7 rows, each row has a button, a label and an entry. The row colors are as follows, top to bottom: neutral, red, orange, yellow, green, blue, purple

    Unlike the HSL color space, Oklab is perceptual and lightness stays uniform regardless of other channels. So, as simple as it sounds, just limiting the lightness does the job. In fact, we could even do this:

    /* light style */
    --accent-color: oklab(from var(--accent-bg-color) 0.5 a b);
    /* dark style */
    --accent-color: oklab(from var(--accent-bg-color) 0.85 a b);

    The downside is that --accent-bg-color: black; in light style would produce a dark gray --accent-color instead of black, and --accent-bg-color: white; in dark style would produce a light gray accent instead of white. This may be fine, but the goal here is to ensure minimum contrast, not to prevent too much contrast.

    These functions are also in the docs, but there’s one problem.

    So why not do it automatically?

    Say, we define these variables at :root, as follows:

    :root {
      --accent-bg-color: var(--blue-3);
      --accent-color: oklab(from var(--accent-bg-color) min(l, 0.5) a b);

    Then, we override accent color for a specific widget:

    my-green-widget {
      --accent-bg-color: var(--green-3);

    But --accent-color would still be blue, so the we would need to re-declare it – not very good.

    There is a way to get around that – use a wildcard:

    * {
      --accent-color: oklab(from var(--accent-bg-color) min(l, 0.5) a b);

    But that has its own downsides – it may impact performance and memory use, like wildcards in CSS tend to do. That said, I haven’t profiled it and maybe it’s not that bad.

    Either way, for now we’re keeping --accent-color separate, but apps overriding it are welcome to use the above functions themselves, instead of picking the color by hand. Maybe in future we’ll figure something out.


    There are a lot more things we could do if we didn’t need to care about backwards compatibility. For example, instead of having colors like --shade-color that are always supposed to be partially-transparent black, we could just provide the opacity as a variable. (or maybe even derive it from background color lightness?) We could specify accent color as a hue and/or chroma in the Oklch color space, while keeping the lightness consistent. And so on.

    Can we drop SCSS entirely?

    A lot of people asked this or assumed that these additions were the few missing pieces for dropping it.

    As much as I’d like to, not yet. While this helps with reducing dependency on it a bit, there are still a lot of things that cannot be replicated, like @mixin and @extend. It also allows us to have private variables and control what gets exposed as API, which is pretty important for a library.

    In fact, there are situations where we had to add more SASS-specific things, tho mostly because we’re using the older (and unmaintained) sassc compiler instead of dart-sass. Being old and unmaintained, sassc doesn’t support the modern rgb() syntax, and errors out. There is a way to placate it, by using RGB() instead, but that’s a hack. It also doesn’t like the slash symbol (well, solidus) and thinks it’s division. This can be worked around with string interpolation, but it’s a hack too.

    So, instead of this:

    rgb(0 0 0 / if($contrast == 'high', 80%, 5%))

    we have to do this:

    RGB(0 0 0 / #{if($contrast == 'high', 80%, 5%)})

    (and then keep in mind that SASS won’t see this as a color, so you can’t use functions like transparentize() on it, not that we really need to)

    Finally, the opacity() function (used within the filter property) kept getting replaced with alpha(), but only when it contained a variable instead of a literal:

    filter: opacity(55%);
    /* SASS output: filter: opacity(55%); */
    filter: opacity(var(--disabled-opacity));
    /* SASS output: filter: alpha(var(--disabled-opacity)); */

    I worked around this by once again manipulating case. opacity() was affected, but Opacity() wasn’t.

    All of this could be solved by migrating to dart-sass. This is difficult, however – GNOME SDK doesn’t have any Dart components at the moment, and it would need to build that first. A lot of manifests I’ve seen on Flathub just use pre-built SASS compiler, but I doubt this would be acceptable for the SDK. So, for now we’re stuck with sassc. Help is very much welcome, particularly with the SDK side of things.

    Programmatic API?

    Another question I see fairly often: is it possible to read variables programmatically?

    The short answer is: no.

    The longer answer is: variables can be anything. The only way to read them would be as a string. At that point, you’d need to have a CSS parser in your app to actually parse them into a useful value.

    For example, let’s say we have a variable declaring a color, like red. One might think: so what, just use gdk_rgba_parse(). Now, what about rgb(0 0 0 / 50%), the modern syntax? gdk_rgba_parse() doesn’t support that, but one might argue it should. Alright, what about this:

    color-mix(in oklab, currentColor, var(--something) calc(var(--base-percentage) * 0.5))

    This is a potentially valid color, and yet there’s no way gdk_rgba_parse() would be able to parse this – how would it know what currentColor is when you don’t supply it a widget? It would need to resolve other variables somehow. And it would also need a full-blown calc() parser. Yeah, colors get complicated fast. It’s fine when we’re already inside a CSS parser, but gdk_rgba_parse() isn’t one.

    Now, could we have a function to get a variable value specifically as a color? Sure, except variables don’t have to be colors. You might also get 3px, 0 or asjdflaskjd. They don’t even have to be valid values, they can also be parts of the values, or even random gibberish. CSS doesn’t even try to compute variables on their own, only insert them into other values when you reference them with var() and then parse and compute that once every reference is resolved. The following is perfectly valid:

    my-widget {
      --space: srgb-linear;
      --r: 100%;
      --gb: 0 0;
      color: color(var(--space) var(--r) var(--gb) / 50%);

    So, with that in mind, would API for fetching them be useful? IMO not really. There are very specific cases where it may work (e.g. if you define a variable containing an integer and then treat it as pixels in your code), but they are far too limited, break easily, and arguably are a misuse of CSS anyway.

    It would be a bit more feasible if we had @property, as then you can at least guarantee the variable type. Even then the type system is very flexible and one can define things like <color># | <integer>#. The valid variables with this type would be comma-separated lists of colors, and comma-separated lists of integers, so good luck with that. And we don’t even need to go that far: take a look at <image>. It can be a gradient (linear (possibly repeating), radial or conic), a URL, image() which produces a solid color image from a given color, or many other things. At best I can see getters being limited to, say, colors, numbers and dimensions.

    Many thanks to:

    • Matthias Clasen for reviews and implementing HWB, Oklch and Oklab color spaces, relative colors, color interpolation and math functions.
    • STF for funding this work.
    • Sonny Piers and Tobias Bernard for organizing everything.

#151 Pride Month

Update on what happened across the GNOME project in the week from May 31 to June 07.

A GNOME window with a pride flag background and a raised first on top of it

This Week in GNOME is dedicated to the struggles of all lesbian, gay, trans, inter, bi, pan, asexual, aromantic, non-binary, and queer people.

LGBTQIA+ people have always been an integral part of our project, across all different roles. We wish to take this opportunity to thank you all from the bottom of our hearts for all your contributions to GNOME and to our community as whole.

We as a project have a fundamental responsibility to ensure the safety and well-being of everyone in our community. This can only be accomplished by prioritizing marginalized people’s safety over privileged people’s comfort. To accomplish this we expect everyone to follow our Code of Conduct, we moderate our chat rooms via cross-community moderation lists and we believe in speaking up whenever something is not right. This takes a remarkable effort every single day, and we still have a lot to learn and to improve. Let us learn and grow together, to become the best we can be.

Our thoughts go out to all the people that have to fight for their right to exist. We stand with you and we fight with you.

Sovereign Tech Fund

Sonny reports

As part of the GNOME STF (Sovereign Tech Fund) initiative, a number of community members are working on infrastructure related projects.

Here are the highlights for the past two weeks:

Tooling and QA

Martin published a post on discourse: Towards a better way to hack and test your system components. Feedback welcome!

Martin made an initial implementation of sysext-utils based on the proposal ahead.

Abderrahim made a GNOME OS single installer image that can install both the ostree and the sysupdate variants. The ostree variant can be dropped when sysupdate is no longer considered experimental.


Alice wrote a blog post about all of the CSS work

Alice landed AdwMultiLayoutView in libadwaita.

Sophie added option to apply image orientation to texture data in glycin.

Sophie split C bindings into libglycin and libglycin-gtk4 and added necessary features such that projects that don’t want/need to depend on GTK (liker mutter) can use glycin without depending on it.


Dorota added an internal API to GNOME Shell that provides additional functionality for managing key grabs, suitable for the GlobalShortcuts portal.

Hub fixed a leak in Flatpak that was spoiling the CLI output.

Hub wrote the Flatpak docs chapter on fallback devices.

António landed many refactors and the part 1 of FileChooser portal implementation for Nautilus.


Matt implemented support for the GtkTextView multi-line text widget in the GTK AccessKit implementation.

Matt fixed a bug in libadwaita that caused the accessibility tree under an AdwTabView or AdwViewStack to be inconsistent, leading to a crash in AccessKit.

Matt started key grabbing protocol support in Mutter/Orca to improve screen reader compatibility in Wayland.

Georges fixed a bug in WebKit where accessible events aren’t notified


Felix added file monitor to Key Rack to watch for Flatpak app keyring changes

Felix landed a major refactor in Key Rack to merge logic for system and flatpak items.

Dhanuka implemented the secret prompt interface in oo7


Andy landed tons of things on GNOME Online Account

Neill Whillans says

More visible CVE reports for gnome-build-meta Recently we have made a few changes to the generation and accessibility of CVE reports for gnome-build-meta.

These changes include the generation of additional CVE reports for both the vm and vm-secure manifests, for master and all future, supported release branches. We also make use of Gitlab Pages to automatically publish not only the CVE reports for the master branch, but also reports for each currently supported release branch. A list of these individual reports can be obtained through a newly added badge that can be found at the top of gnome-build-meta’s README.

This work was carried out as part of Codethink’s collaboration with the GNOME Foundation, through the Sovereign Tech Fund (STF).

GNOME Core Apps and Libraries


Cross-platform widget toolkit for creating graphical user interfaces.

Alice (she/her) reports

I wrote a blog post about the recent work in GTK to modernize its CSS engine, and the implications for apps using GTK and libadwaita: https://blogs.gnome.org/alicem/2024/06/07/css-happenings/

GNOME Incubating Apps

Sophie (she/her) reports

Showtime has been accepted into the GNOME Incubator. The GNOME incubation process is for apps that are designated to be accepted into GNOME Core or GNOME Development Tools if they reach the required maturity.

Showtime is slated to replace Totem, GNOME’s current video app. The reason is that Totem has now been unmaintained for nearly a year and still uses GTK 3.

You can help improve Showtime by testing the nightly version and contributing. The incubation progress will be tracked in this issue.

GNOME Circle Apps and Libraries


Travel with all your train information in one place.

Markus Göllnitz says

We have some great news about Railway! @schmiddi:matrix.org has done a tremendous job at boring up the backend code of the application, as well as its library counterpart. Railway is no longer limited to the HAFAS API. 🎉 That is not just a theoretical improvement: As the first newly supported network, you can test the Swiss SBB through search.ch.

If you use Railway and want to test this new network, or want to help us make sure we did not introduce obscure regressions, be sure to test our Railway beta release on Flathub beta: flatpak install https://flathub.org/beta-repo/appstream/de.schmidhuberj.DieBahn.flatpakref. If you do test it: Thank You! And feel free to share feedback with us over at #railwayapp:matrix.org or at our issue tracker.

Aaaand … @schmiddi:matrix.org even went so far as to implement support for MOTIS. You never heard of that? It is used by an open data based routing project: the Transitous project. As they say about themselves, “Transitous is a community-run provider-neutral international public transport routing service.” If you hate the need to change the network in Railway, care about FLOSS server-side as much as client-side, and want to see open data in open formats, such as GTFS, excel, you will love this. In the beta release, you can find it as “Worldwide (beta) using Transitous,” but bear in mind that official providers are still more accurate, more up-to-date, and will stay for a reason. If you want to see that changed, you can get involved with said project.


Safe bindings to the Rust language for fundamental libraries from the GNOME stack.

Bilal Elmoussaoui says

It took a bit too long but we have finally released a blog post that covers the changes that landed in the latest Rust bindings release. https://gtk-rs.org/blog/2024/06/01/new-release.html

Third Party Projects

Nokse reports

I have released Exhibit, an app to view 3D models, powered by F3D.

Some of the features are:

  • Support for many file formats, including glTF, USD, STL, STEP, PLY, OBJ, FBX, Alembic and many more
  • Many rendering and visual settings
  • HDRI or colored background
  • Export render to image
  • Drag and drop files
  • It installs mimetype and icon for supported file types

For now it only works with X11/Xwayland because the library can only be compiled to work with one compositor at a time.

Daniel Wood announces

Design - 2D CAD for GNOME has recieved an update with lots of changes. This update forms a foundation for more advanced drawing entities like dimensions. Highlights include:

  • Manage text and line styles from the preferences window
  • Update text and line style from the properties window
  • Highlight design entities on mouse hover
  • Fix opening files as arguments e.g. ‘open with’ from file browser
  • Improve Trim and Extend command selection highlighting
  • Fix behaviour when no commands have been performed
  • Prevent selection of items on locked or frozen layers
  • Fix ortho and polar snaps when typed point data is entered
  • Update rotate command to match typical workflow
  • Underline shortcut letter of command options
  • Use consistent prompt for command with options
  • Remove custom headerbar buttons from layers window
  • Use RGB colours internally for all colour definitions
  • Support DXF true colours
  • Fix issue with layers being updated with incorrect state when editing layer data
  • Draw entities using correct colour when part of a block, supporting colour ‘ByBlock’
  • Add Block command, enabling creation of blocks
  • Add Explode command, enabling decomposition of blocks into primitive entities
  • Add Hatch command and common hatch patterns
  • Update to the latest GNOME dev kit icons
  • Add Purge command, clearing unused, blocks, layers and line types
  • Show suggestions for invalid command input

Get it on Flathub: https://flathub.org/apps/io.github.dubstar_04.design


Practice your typing skills

Brage Fuglseth reports

How fast can you type? Find out with my new app, Keypunch!

I’ve worked on this for the last couple of months, and it’s finally out. Keypunch lets you practice your typing skills with automatically generated pseudo-text in your language of choice. Alternatively, you can supply it with your own text, such as song lyrics, Wikipedia articles, and quotes. Get ready to accelerate your typing speed!

Get it on Flathub: https://flathub.org/apps/dev.bragefuglseth.Keypunch

Shell Extensions

Arca says

Day Progress: an extension that shows a progress bar of your day to help you track your time.

I actually released this last week, but it took another week for it to become stable enough to call it a stable release. Here’s how it works: you set the start and reset (end) times in the extension preferences (for example, the start and end of your workday) and it displays a progress bar of the current time in the top panel.


  • Customisable start and end times, including the ability to wrap around midnight
  • Option to show time elapsed instead of remaining
  • Customisable bar width and height
  • Option to display a bar with smooth, curved ends (experimental)
  • Customisable panel position and index
  • Shows percentage and time elapsed and remaining in the tooltip (see image below)

You can download the extension at: https://extensions.gnome.org/extension/7042/day-progress/ The GitHub repository is at: https://github.com/ArcaEge/day-progress

screenshot image


Pablo Correa Gomez announces

as part of GSoC camelCaseNick landed support for floating zoom buttons in Papers! This design pattern was part of the mockups for more than 5 years, but was never implemented! This is a first step to make the top bar fitting on mobile!


Asmit Malakannawar reports

Hello everyone,

We’re thrilled to announce that the call for volunteers and the call for BoFs for GUADEC 2024 is now open!

If you’re passionate about making GUADEC 2024 a success and want to lend a helping hand, please fill out the volunteer form.

For those interested in presenting a workshop or leading a Birds of a Feather (BoF) session, we’d love to hear from you! Please fill out the BoFs form to submit your proposal.

Volunteer Form Link BoFs Form Link

GNOME Foundation

Rosanna reports

My week has been very busy with financial things. I had meetings with our bookkeeper and our accountant. With their support, our books have never looked as good as they do now. In addition, working within our board-approved balanced budget has meant that our numbers look healthier as well. This point was made more apparent to me when our accountant asked if we had considered finding higher interest accounts for our funds. More research on this is now on my to-do list.

The Foundation’s Strategic Plan Draft https://foundation.gnome.org/strategicplan/ is still open for feedback. Please submit using the link on that page. While we value all feedback, having it all in one place makes it easier for us to make sure we don’t lose any of your views.

If you haven’t registered for GUADEC yet, please do so: https://events.gnome.org/event/209/registrations/! The earlier we know how many people are coming, the easier it will be for us to plan. And don’t forget to register for the baseball game as well. Go Red Sox!

We are still looking for more sponsors for GUADEC. If you or your employer are interested, please let us know!

Caroline Henriksen reports

In honor of Pride Month, we’d like to give a special shout out to our LGBTQIA+ community. Thank you for contributing your voices and efforts to GNOME, we appreciate all of your hard work!

We’d also like to invite everyone to join us in celebrating Pride Month at a special GNOME Social Hour on June 24 at 17:30 UTC. Come chat with contributors and Foundation members, and share ideas on how we can better support our LGBTQIA+ community. https://discourse.gnome.org/t/celebrate-pride-month-at-the-gnome-social-hour-june-24/21421

That’s all for this week!

See you next week, and be sure to stop by #thisweek:gnome.org with updates on your own projects!

June 06, 2024

GSoC’24 Introductory Blog

Hello GNOME Community!

I am Divyansh Jain, a computer science student at IIT Roorkee, India. I also go by my hacker alias, Demigod, whenever I am programming. I really love tech, and any new advancements in technology excite me.

When I’m not programming, I love to cook, sleep, and read about politics.

I’m honored to join the GNOME community as a Google Summer of Code (GSoC) contributor this year. I’ll be developing a web-based tool for writing and running SPARQL queries within Tracker (now TinySPARQL). I will be mentored by Carlos Garnacho and Sam Thursfield.

Introducing the Tool

SPARQL is a query language used to retrieve data from databases that store information in a specific format (RDF). This tool aims to simplify writing and running these queries directly in a web browser, eliminating the need for the command line. Additionally, it will present the results in a visually appealing format, enhancing readability and user experience.

Benefits for Everyone

This project will significantly improve the experience for those using libtracker-sparql to interact with RDF databases. By lowering the barrier to entry for newcomers, boosting developer productivity with visual editing, and fostering collaboration through easier query sharing, this web IDE promises a more streamlined workflow.

Looking Forward!

I’m excited for a summer full of learning and collaborating with the GNOME community. Updates on the project’s progress will be shared soon!

goodbye xsetwacom, hello gsetwacom

Back in the day when presumably at least someone was young, the venerable xsetwacom tool was commonly used to configure wacom tablets devices on Xorg [1]. This tool is going dodo in Wayland because, well, a tool that is specific to an X input driver kinda stops working when said X input driver is no longer being used. Such is technology, let's go back to sheep farming.

There's nothing hugely special about xsetwacom, it's effectively identical to the xinput commandline tool except for the CLI that guides you towards the various wacom driver-specific properties and knows the right magic values to set. Like xinput, xsetwacom has one big peculiarity: it is a fire-and-forget tool and nothing is persistent - unplugging the device or logging out would vanish the current value without so much as a "poof" noise [2].

If also somewhat clashes with GNOME (or any DE, really). GNOME configuration works so that GNOME Settings (gnome-control-center) and GNOME Tweaks write the various values to the gsettings. mutter [3] picks up changes to those values and in response toggles the X driver properties (or in Wayland the libinput context). xsetwacom short-cuts that process by writing directly to the driver but properties are "last one wins" so there were plenty of use-cases over the years where changes by xsetwacom were overwritten.

Anyway, there are plenty of use-cases where xsetwacom is actually quite useful, in particular where tablet behaviour needs to be scripted, e.g. switching between pressure curves at the press of a button or key. But xsetwacom cannot work under Wayland because a) the xf86-input-wacom driver is no longer in use, b) only the compositor (i.e. mutter) has access to the libinput context (and some behaviours are now implemented in the compositor anyway) and c) we're constantly trying to think of new ways to make life worse for angry commenters on the internets. So if xsetwacom cannot work, what can we do?

Well, most configurations possible with xsetwacom are actually available in GNOME. So let's make those available to a commandline utility! And voila, I present to you gsetwacom, a commandline utility to toggle the various tablet settings under GNOME:

$ gsetwacom list-devices
- name: "HUION Huion Tablet_H641P Pen"
  usbid: "256C:0066"
- name: "Wacom Intuos Pro M Pen"
  usbid: "056A:0357"
$ gsetwacom tablet "056A:0357" set-left-handed true
$ gsetwacom tablet "056A:0357" set-button-action A keybinding "<Control><Alt>t"
$ gsetwacom tablet "056A:0357" map-to-monitor --connector DP-1

Just like xsetwacom was effectively identical to xinput but with a domain-specific CLI, gsetwacom is effectively identical to the gsettings tool but with a domain-specific CLI. gsetwacom is not intended to be a drop-in replacement for xsetwacom, the CLI is very different. That's mostly on purpose because I don't want to have to chase bug-for-bug compatibility for something that is very different after all.

I almost spent more time writing this blog post than on the implementation so it's still a bit rough. Also, (partially) due to how relocatable schemas work error checking is virtually nonexistent - if you want to configure Button 16 on your 2-button tablet device you can do that. Just don't expect 14 new buttons to magically sprout from your tablet. This could all be worked around with e.g. libwacom integration but right now I'm too lazy for that [4]

Oh, and because gsetwacom writes the gsettings configuration it is persistent, GNOME Settings will pick up those values and they'll be re-applied by mutter after unplug. And because mutter-on-Xorg still works, gsetwacom will work the same under Xorg. It'll also work under the GNOME derivatives as long as they use the same gsettings schemas and keys.

Le utilitaire est mort, vive le utilitaire!

[1] The git log claims libwacom was originally written in 2009. By me. That was a surprise...
[2] Though if you have the same speakers as I do you at least get a loud "pop" sound whenever you log in/out and the speaker gets woken up
[3] It used to be gnome-settings-daemon but with mutter now controlling the libinput context this all moved to mutter
[4] Especially because I don't want to write Python bindings for libwacom right now

June 05, 2024

Manuals on Flathub

Manuals contains the documentation engine from Builder as a standalone application. Not only does it browse documentation organized by SDK but can install additional SDKs too. This is done using the same techniques Builder uses to manage your project SDKs.

It should feel very familiar if you’re already using the documentation tooling in Builder.

In the past, we would just parse all the *.devhelp2 files up-front when loading. GMarkupParseContext is fast enough that it isn’t too much overhead at start-up for a couple hundred files.

However, once you start dealing with SDKs and multiple versions of all these files the startup performance can take quite a hit. So Manuals indexes these files into SQLite using GOM and performs queries using that instead. It conveniently makes cross-referencing easy too so you can jump between SDK revisions for a particular piece of documentation.


More ways to install software in SteamOS: Distrobox and Nix


In my previous post I talked about how to use systemd-sysext to add software to the Steam Deck without modifying the root filesystem. In this post I will give a brief overview of two additional methods.


distrobox is a tool that uses containers to create a mutable environment on top of your OS.

Distrobox running in SteamOS

With distrobox you can open a terminal with your favorite Linux distro inside, with full access to the package manager and the ability to install additional software. Containers created by distrobox are integrated with the system so apps running inside have normal access to the user’s home directory and the Wayland/X11 session.

Since these containers are not stored in the root filesystem they can survive an OS update and continue to work fine. For this reason they are particularly suited to systems with an immutable root filesystem such as Silverblue, Endless OS or SteamOS.

Starting from SteamOS 3.5 the system comes with distrobox (and podman) preinstalled and it can be used right out of the box without having to do any previous setup.

For example, in order to create a Debian bookworm container simply open a terminal and run this:

$ distrobox create -i debian:bookworm debbox

Here debian:bookworm is the image that this container is created from (debian is the name and bookworm is the tag, see the list of supported tags here) and debbox is the name that is given to this new container.

Once the container is created you can enter it:

$ distrobox enter debbox

Or from the ‘Debian’ entry in the desktop menu -> Lost & Found.

Once inside the container you can run your Debian commands normally:

$ sudo apt update
$ sudo apt install vim-gtk3


Nix is a package manager for Linux and other Unix-like systems. It has the property that it can be installed alongside the official package manager of any distribution, allowing the user to add software without affecting the rest of the system.

Nix running in SteamOS

Nix installs everything under the /nix directory, and packages are made available to the user through a new entry in the PATH and a ~/.nix-profile symlink stored in the home directory.

Nix is more things, including the basis of the NixOS operating system. Explaning Nix in more detail is beyond the scope of this blog post, but for SteamOS users these are perhaps its most interesting properties:

  • Nix is self-contained: all packages and their dependencies are installed under /nix.
  • Unlike software installed with pacman, Nix survives OS updates.
  • Unlike podman / distrobox, Nix does not create any containers. All packages have normal access to the rest of the system, just like native SteamOS packages.
  • Nix has a very large collection of packages, here is a search engine: https://search.nixos.org/packages

The only thing that Nix needs from SteamOS is help to set up the /nix directory so its contents are not stored in the root filesystem. This is already happening starting from SteamOS 3.5 so you can install Nix right away in single-user mode:

$ sudo chown deck:deck /nix
$ wget https://nixos.org/nix/install
$ sh ./install --no-daemon

This installs Nix and adds a line to ~/.bash_profile to set up the necessary environment variables. After that you can log in again and start using it. Here’s a very simple example (refer to the official documentation for more details):

# Install and run Midnight Commander
$ nix-env -iA nixpkgs.mc
$ mc

# List installed packages
$ nix-env -q

# Uninstall Midnight Commander
$ nix-env -e mc-4.8.31

What we have seen so far is how to install Nix in single-user mode, which is the simplest one and probably good enough for a single-user machine like the Steam Deck. The Nix project however recommends a multi-user installation, see here for the reasons.

Unfortunately the official multi-user installer does not work out of the box on the Steam Deck yet, but if you want to go the multi-user way you can use the Determinate Systems installer: https://github.com/DeterminateSystems/nix-installer


Distrobox and Nix are useful tools and they give SteamOS users the ability to add additional software to the system without having to modify the base operating system.

While for graphical applications the recommended way to install third-party software is still Flatpak, Distrobox and Nix give the user additional flexibility and are particularly useful for installing command-line utilities and other system tools.

June 04, 2024

Red Hat Day of Learning

Occasionally at Red Hat we have a “Day of Learning” where we get to spend time learning about technology of our choice.

I spent some time listening to various AI explanations which were suggested readings for the day. Nothing too surprising but also not exactly engaging to me. Maybe that’s because I grew up with a statistics professor for a father.

So while that was playing I spent a little time learning how the GitLab API works. Immediately it stood out that one of the primary challenges in presenting UI for such an API would be in bridging GListModel to their implementation.

So I spent a little time on the architecture for how you might want to do that in the form of a Gitlab-GLib library.


There are essentially two modes of pagination supported by GitLab depending on the result set size. Both methods use HTTP headers to denote information about the result set.

Importantly, any design would want to have an indirection object (and in this case GitlabListItem) which can have it’s resource dynamically loaded.

Resources (such as a GitlabProject, or GitlabIssue) are “views” into the JSON result set. They are only used for reading, not for mutating or creating resources on the API server.

Offset-based Pagination

This form is somewhat handy because you can know the entire result-set size up front. Then you can back-fill entries as accessed by the user using bucketed lazy-loading.

When the bucketed page loads, the indirection objects are supplied with their resource object which provides a typed API over the JsonNode backing it.

This is the “ideal” form from the consuming standpoint but can put a great deal of load on the GitLab server instance.

Progressive Pagination

The other form of pagination lets you fetch the next page after each subsequent request. The header provides the next page number.

One might expect that you could use this to still jump around to the appropriate page. However if you are not provided the “number of pages” header from the server then there is not much you can do to clamp your page range.


This was a fun little side-project to get to know some of the inner workings of the API backing what those of us in GNOME use every day. I have no idea if anything will come of it, but it certainly could be useful from Builder if anyone has time to run with it.

For example, imagine having access to common GitLab operations from the header bar.

A screenshot of GNOME Builder with a new GtkMenuButton in the headerbar containing a GitLab icon and menu.

GUADEC 2024 Call for BoFs and Workshops

We have opened an additional call for submissions for Birds-of-a-Feather (BoF) sessions and Workshops for GUADEC 2024!

BoF and Workshop sessions will be scheduled in one or two-hour blocks on Monday, July 22, and Tuesday, July 23. If you’re interested in hosting a session on either of these days, please fill out this form to apply. If you previously submitted a proposal during the call for proposals, your request has already been included in the conference schedule. The deadline for new submissions is 15th June.

GUADEC 2024 will take place at Tivoli Student Union in the Auraria Campus. For more information, visit guadec.org.

Please note that BoFs and Workshops will not be live-streamed. Sessions can be held either remotely or in person, GUADEC BoF rooms on meet.gnome.org will be available for each track. If you are hosting in person and want to allow remote attendance you will need to use your own computers, cameras, and microphones to connect to the remote conference room.

We look forward to receiving your BoF and Workshop proposals and making GUADEC 2024 a memorable event for everyone. For more details or to register, please visit guadec.org.

We can’t wait to see you at GUADEC 2024!

June 03, 2024

Libadwaita: Splitting GTK and Design Language


Recently, the Linux Mint Blog published Monthly News – April 2024, which goes into detail about wanting to fork and maintain older GNOME apps in collaboration with other GTK-based desktop environments.

Despite the good intentions of the author, Clem, many readers interpreted this as an attack against GNOME. Specifically: GTK, libadwaita, the relationship between them, and their relevance to any desktop environment or desktop operating system. Unfortunately, many of these readers seem to have a lot of difficulty understanding what GTK is trying to be, and how libadwaita helps.

In this article, we’ll look at the history of why and how libadwaita was born, the differences between GTK 4 and libadwaita in terms of scope of support, their relevance to each desktop environment and desktop operating system, and the state of GTK 4 today.

What Is GTK?

First of all, what is GTK? GTK is a cross-platform widget toolkit from the GNOME Project, which means it provides interactive elements that developers can use to build their apps.

The latest major release of GTK is 4, which brings performance improvements over GTK 3. GTK 4 also removes several widgets that were part of the GNOME design language, which became a controversy. In the context of application design, a design language is the visual characteristics that are communicated to the user. Fonts, colors, shapes, forms, layouts, writing styles, spacing, etc. are all elements of the design language.(Source)

Unnecessary Unification of the Toolkit and Design Language

In general, cross-platform toolkits tend to provide general-purpose/standard widgets, typically with a non-opinionated styling, i.e. widgets and design patterns that are used consistently across different operating systems (OSes) and desktop environments.

However, GTK had the unique case of bundling GNOME’s design language into GTK, which made it far from generic, leading to problems of different lexicons, mainly philosophical and technical problems.

Clash of Philosophies

When we look at apps made for the GNOME desktop (will be referred to as “GNOME apps”) as opposed to non-GNOME apps, we notice that they’re distinctive: GNOME apps tend to have hamburger buttons, header bars, larger buttons, larger padding and margins, etc., while most non-GNOME apps tend to be more compact, use menu bars, standard title bars, and many other design metaphors that may not be used in GNOME apps.

This is because, from a design philosophy standpoint, GNOME’s design patterns tend to go in a different direction than most apps. As a brand and product, GNOME has a design language it adheres to, which is accompanied by the GNOME Human Interface Guidelines (HIG).

As a result, GTK and GNOME’s design language clashed together. Instead of being as general-purpose as possible, GTK as a cross-platform toolkit contained an entire design language intended to be used only by a specific desktop, thus defeating the purpose of a cross-platform toolkit.

For more information on GNOME’s design philosophy, see “What is GNOME’s Philosophy?”.

Inefficient Diversion of Resources

The unnecessary unification of the toolkit and design language also divided a significant amount of effort and maintenance: Instead of focusing solely on the general-purpose widgets that could be used across all desktop OSes and environments, much of the focus was on the widgets that were intended to conform to the GNOME HIG. Many of the general-purpose widgets also included features and functionality that were only relevant to the GNOME desktop, making them less general-purpose.

Thus, the general-purpose widgets were being implemented and improved slowly, and the large codebase also made the GNOME widgets and design language difficult to maintain, change, and adapt. In other words, almost everything was hindered by the lack of independence on both sides.

Libhandy: the Predecessor

Because of the technical bottlenecks caused by the philosophical decisions, libhandy was created in 2017, with the first experimental version released in 2018. As described on the website, libhandy is a collection of “[b]uilding blocks for modern adaptive GNOME applications.” In other words, libhandy provides additional widgets that can be used by GNOME apps, especially those that use GTK 3. For example, Boxes uses libhandy, and many GNOME apps that used to use GTK 3 also used libhandy.

However, some of the problems remained: Since libhandy was relatively new at the time, most GNOME widgets were still part of GTK 3, which continued to suffer from the consequences of merging the toolkit and design language. Furthermore, GTK 4 was released at the end of December 2020 — after libhandy. Since libhandy was created before the initial release of GTK 4, it made little sense to fully address these issues in GTK 3, especially when doing so would have caused major breakages and inconveniences for GTK, libhandy, and app developers. As such, it wasn’t worth the effort.

With these issues in mind, the best course of action was to introduce all these major changes and breakages in GTK 4, use libhandy as an experiment and to gain experience, and properly address these issues in a successor.

Libadwaita: the Successor

Because of all the above problems, libadwaita was created: libhandy’s successor that will accompany GTK 4.

GTK 4 was initially released in December 2020, and libadwaita was released one year later, in December 2021. With the experience gained from libhandy, libadwaita managed to become extensible and easy to maintain.

Libadwaita is a platform library accompanying GTK 4. A platform library is a library used to complement a specific platform. In the case of libadwaita, the platform it targets is the GNOME desktop.

Porting Widgets to Libadwaita

Some GNOME widgets from GTK 3 (or earlier versions of GTK 4) were removed or deprecated in GTK 4 and were reimplemented in / transferred to libadwaita, for example:

These aforementioned widgets only benefited GNOME apps, as they were strictly designed to provide widgets that conformed to the GNOME HIG. Non-GNOME apps usually didn’t use these widgets, so they were practically irrelevant to everyone else.

In addition, libadwaita introduced several widgets as counterparts to GTK 4 to comply with the HIG:

Similarly, these aforementioned GTK 4 (the ones starting with Gtk) widgets are not designed to comply with the GNOME HIG. Since GTK 4 widgets are supposed to be general-purpose, they should not be platform-specific; the HIG no longer has any influence on GTK, only on the development of libadwaita.

Scope of Support

The main difference between GTK 4 and libadwaita is the scope of support, specifically the priorities in terms of the GNOME desktop, and desktop environment and OS support. While most resources are dedicated to GNOME desktop integration, GTK 4 is not nearly as focused on the GNOME desktop as libadwaita. GTK 4, while opinionated, still tries to get closer to the traditional desktop metaphor by providing these general-purpose widgets, while libadwaita provides custom widgets to conform to the GNOME HIG.

Since libadwaita is only made for the GNOME desktop, and the GNOME desktop is primarily officially supported on Linux, libadwaita thus primarily supports Linux. In contrast, GTK is officially supported on all major operating systems (Windows, macOS, Linux). However, since GTK 4 is mostly developed by GNOME developers, it works best on Linux and GNOME — hence “opinionated”.

State of GTK 4 Today

Thanks to the removal of GNOME widgets from GTK 4, GTK developers can continue to work on general-purpose widgets, without being influenced or restricted in any way by the GNOME HIG. Developers of cross-platform GTK 3 apps that rely exclusively on general-purpose widgets can be more confident that GTK 4 won’t remove these widgets, and hopefully enjoy the benefits that GTK 4 offers.

At the time of writing, there are several cross-platform apps that have either successfully ported to GTK 4, or are currently in the process of doing so. To name a few: Freeciv gtk4 client, HandBrake, Inkscape, Transmission, and PulseAudio Volume Control. The LibreOffice developers are working on the GTK 4 port, with the gtk4 VCL plugin option enabled. For example, the libreoffice-fresh package from Arch Linux has it enabled.

Here are screenshots of the aforementioned apps:

Freeciv gtk4 client in the game view, displaying a title bar, a custom background, a menu bar, a tab view with the Chat tab selected, an entry, and a few buttons.

HandBrake in the main view, displaying a title bar, a menu bar, a horizontal toolbar below it with custom buttons, entries, popover buttons, a tab view with the Summary tab selected, containing a popover button and several checkboxes.

Development version of Inkscape in the main view, displaying a title bar, a menu bar, a horizontal toolbar below, vertical toolbars on the left and right, a canvas grid on the center left, a tab view on the center right with the Display Properties tab selected, and a toolbar at the bottom.

LibreOffice Writer with the experimental gtk4 VCL plugin in workspace view, displaying a title bar, a menu bar, two horizontal toolbars below, a vertical toolbar on the right, a workspace grid in the middle with selected text, and a status bar at the bottom.

Transmission in the main view, displaying a title bar, a menu bar, a horizontal toolbar, a filter bar, an empty field in the center of the view, and a status bar at the bottom.

PulseAudio Volume Control in the Output Devices view, displaying a title bar, a tab section, a list of output devices, and a bottom bar with a combo box.

A GNOME App Remains a GNOME App, Unless Otherwise Stated

This is a counter-response to Thom Holwerda’s response to this article.

An app targeting a specific platform will typically run best on that platform and will naturally struggle to integrate with other platforms. Whether the libraries change over time or stay the same forever, if the developers are invested in the platform they are targeting, the app will follow the direction of the platform and continue to struggle to integrate with other platforms. At best, it will integrate in other platforms by accident.

In this case, developers who have and will continue to target the GNOME desktop will actively adapt their apps to follow the GNOME philosophy, for better or worse. Hamburger buttons, header bars, typography, and distinct design patterns were already present a decade ago (2014).(Source) Since other platforms were (and still are) adhering to different design languages, with or without libhandy/libadwaita, the GTK 3 apps targeting GNOME were already distinguishable a decade ago. Custom solutions such as theming were (and still are) inadequate, as there was (and still is) no 🪄 magical 🪄 solution that converts GNOME’s design patterns into their platform-agnostic counterparts.

Whether the design language is part of the toolkit or a separate library has no effect on integration, because GNOME apps already looked really different long before libhandy was created, and non-GNOME apps already looked “out of place” in GNOME as well. Apps targeting a specific platform that unintentionally integrate with other platforms will eventually stop integrating with other platforms as the target platform progresses and apps adapt. In rare cases, developers may decide to no longer adhere to the GNOME HIG.

Alternate Platforms

While libadwaita is the most popular and widely used platform library that accompanies GTK 4, there are several alternatives to libadwaita:

There are also several alternatives to libhandy:

  • libxapp is developed and maintained by Linux Mint, and focuses on multiple GTK desktop environments, such as Cinnamon, MATE, and Xfce.
  • libxfce4ui is developed and maintained by Xfce, and focuses on Xfce.

Just like libadwaita and libhandy, these platform libraries offer custom widgets and styling that differ from GTK and are built for their respective platforms, so it’s important to realize that GTK is meant to be built with a complementary platform library that extends its functionality when targeting a specific platform.

Similarly, Kirigami from KDE accompanies Qt to build Plasma apps. MauiKit from the Maui Project (another KDE project) also accompanies Qt, but targets Nitrux. Libcosmic by System76 accompanies iced to build COSMIC apps.


A cross-platform toolkit should primarily provide general-purpose widgets. Third parties should be able to extend the toolkit as they see fit through a platform library if they want to target a specific platform.

As we’ve seen throughout the philosophical and technical issues with GTK, a lot of effort has gone into moving GNOME widgets from GTK 4 to libadwaita. GTK 4 will continue to provide these general-purpose widgets for apps intended to run on any desktop or OS, while platform libraries such as libadwaita, Granite and libhelium provide styling and custom widgets that respect their respective platforms.

Libadwaita is targeted exclusively at the GNOME ecosystem, courtesy of the GNOME HIG. Apps built with libadwaita are intended to run best on GNOME, while GTK 4 apps that don’t come with a platform library are intended to run everywhere.

  1. The core functionality of GtkDialog, i.e. creating dialogs, has been moved to GtkWindow

May 31, 2024

Exciting Updates on the GNOME Development Initiative and Sovereign Tech Fund

GNOME Foundation Executive Director Holly Million had a call this week with Tara Tarakiyee, our program manager at Sovereign Tech Fund (STF), providing him with an update on the project work taking place under the Foundation’s current contract with STF and the Foundation’s plans to continue and expand the work. We’re thrilled to share those updates with the greater community here!

Key Updates

  • The contracted work continues to progress, and the Sovereign Tech Fund is very encouraged by what has been accomplished to date.
  • The areas of work currently being funded by STF are planned to continue and to be strengthened and expanded as part of our new, permanent GNOME Development Initiative, as described in our draft strategic plan: foundation.gnome.org/strategicplan
  • The Foundation is reorganizing the project and hiring an additional program manager to work with current managers on the new Initiative. We are finalizing a contract for transitional work with the new manager and will make a formal announcement next week.
  • We hope to significantly increase the amount of development work happening through the Initiative with a process that allows community suggestions for needed work and an application process for grants for proposed work.
  • The Foundation recently applied to the Open Tech Fund to strengthen the Initiative, including proposing to hire a permanent full-time program manager and to invest in other important work to support our community
  • The Foundation will apply for a new round of contract funding when the Sovereign Tech Fund reopens for applications in mid-June. 
  • We have launched the GNOME Development Fund, which will raise additional support from the community to fuel the development work possible through the Initiative. Starting immediately, all donations made through the Fund will build the Initiative. This Fund page will continue to develop, with counters, a backer list, tiered benefits for backers at differing levels, and badges coming next. Donate today to support the future of GNOME. gnome.org/donate

In other exciting news, the Foundation has new professional bookkeeping systems in place, completed a financial review in preparation for a required financial audit next year, and at the completion of the second quarter of this fiscal year, the Foundation is performing under budget and is on track in our commitment to having a non-deficit year. We will share more details, including graphs and financial details in a separate update soon.

May 29, 2024

rpmlint: Google Summer of Code 2024

I'm glad to say that I'll participate again in the GSoC, as mentor. This year we will continue the work done during the past year, as part of the openSUSE project.

So this summer I'll be mentoring an intern and we'll continue working on improving the testing framework of the rpmlint project.

This year we've a better testing framework, thanks to the work done during the past Summer of Code, by Afrid. So the goal for this year is to try to modernize existing tests and remove as much files as possible from test/binary directory, replacing those with mock packages defined with python code.

The selected intern is Luz Marina Montilla Marín. She has done some initial work in the rpmlint project, creating the mock packages for some tests and we've just started with the work to do during the GSoC program, evaluating the tests that we've right now and planning were to start.

She studies at Córdoba, Spain, my hometown. Every year I try to reach young people at different local universities, here in Andalucía, and sometimes I'm able to convince some students to participate, like the GSoC 2020, when Alejandro Dominguez, from Seville, were working on Fractal. So I'm happy that I'm increasing the number of free software developers in my local community :D

I'm sure that she will be able to achieve great things during these three months, so I'm looking forward to start to code and see how far can we go.

Hello Planet Gnome!

Hello World!

My name is Tamnjong Larry, and I live in a moderately sized town in Cameroon called Bamenda. My primary experience in the tech field has been in backend development using .NET and Java. Despite my focus on backend development, I believe the true magic in software happens when users interact with the interface — clicking buttons, scrolling bars, switching tabs, and more.

Seeing users interact with systems and how intuitive designs make their lives easier, I found a deeper fulfillment.

I have always been interested in open source. My new passion for design and understanding user behavior gave me an added boost to get involved in open source, which is the best place to learn from actual experts building interfaces that millions of people use. I applied to the Outreachy May to August 2024 cohort. I found the GNOME project, “Conduct a series of short user research exercises, using a mix of research methods,” to be the best match for my goal of learning about the UI/UX design process. I love interacting with people, asking questions, and understanding them.

I believe in:

Adventure: I should try out new things.
Contribution: I should be able to give back to the world something of value, no matter how small it is.
Optimism: Tomorrow is always better than today as long as I don’t give up today.

I am happy to be part of the amazing GNOME community. Over the next few months, I will share my journey here.

I am excited to be working with amazing mentors, Allan Day and Aryan Kaushik.

May 28, 2024

Workbench News


Workbench is now available on the GNOME nightly repository.

Please prefer Workbench from Flathub but if you're a GNOME contributor, Workbench nightly can come handy

flatpak remote-add --if-not-exists gnome-nightly https://nightly.gnome.org/gnome-nightly.flatpakrepo
flatpak install gnome-nightly re.sonny.Workbench.Devel

It is the first app on GitHub to be available on GNOME nightly. Thanks to Jordan Petridis and Bilal Elmoussaoui for the help.


I'm very happy to announce that as of yesterday we are mentoring 2 students on Workbench.

Angelo Verlain (aka vixalien) is a student from Kigali, Rwanda. Angelo is already a GNOME Foundation member and made significant contributions including an audio player app “Decibels” that is being incubated to join GNOME core apps.

Bharat Tyagi is a student from Jaipur, India. Bharat made great contributions to Workbench during the GSoC contribution period, and I'm looking forward to seeing more of it. You can read their introduction here.

Angelo is working on TypeScript support in Workbench and GNOME.

Bharat is working on porting remaining demos to Vala, redesigning the Library and add code search to it.

Very happy working with both of them

GNOME will have two Outreachy interns conducting a series of short user research exercises

We are happy to announce that GNOME is sponsoring two Outreachy internship projects for the May-August 2024 Outreachy internship round where they will be conducting a series of short user research exercises, using a mix of research methods.

Udo Ijibike and Tamnjong Larry Tabeh will be working with mentors Allan Day and Aryan Kaushik.

Stay tuned to Planet GNOME for future updates on the progress of this project!

Recovering the BIOS on a Dell XPS 13 (9310)

It seems like every few months my work Dell XPS 13 just… dies. Or at least, it seems like it for a few minutes, making me panic about being able to do my work and wondering about backups. And then I remember that it just likes to play dead for no reason—maybe I recently did a BIOS update, maybe I had to open its chassis for some reason (like a jittery trackpad… another blog post I need to write), maybe the battery was totally discharged, or maybe it just wants to troll me. Idk. But it happens more regularly than it should.

The symptoms are more or less the same:

  1. It doesn’t turn on

  2. If it does turn on (e.g. after leaving it plugged in for a while and/or holding the power button), I get a Dell logo and some blinking lights

  3. If I disconnect the battery and try to boot up, I get other blinky lights and/or an exciting RGB rave on the display

  4. The BIOS is just… inaccessible

Perhaps the most frustrating thing about this situation is that Dell’s own documentation is terrible. They lean too heavily on forums with bad advice, their support site is hard to search, and different documentation will tell you to do different things for no discernible reason. The service manual is hard to find and has some useful information, but then too often tells you to contact their technical support—who will refuse to help if it’s out of warranty.

I last documented how to recover from this on Mastodon when it happened to me in December, but surprise, it happened to me again! At this point I figured I’d make it more easily searchable/findable by documenting in a blog post. Here goes.

Charge the Battery

First, if your Dell XPS is failing to boot, try plugging it into power for an hour or so, then try booting after that. It’s possible the battery is just low and the laptop is refusing to boot—I’ve had this more than once, and the laptop frustratingly does a bad job of telling you what’s happening—and it seems to require being charged up more than just a little bit to turn back on after this happens.

I don’t know why you can’t just connect power and boot up with a dead battery; I guess that would be too easy, and Dell prefers you to waste an hour without being able to use your computer. Neat stuff!

If you’ve done this and still just get the Dell logo (and maybe some blinky lights from the battery/status LED strip below the trackpad), carry on. But note that you need at least 10–15% battery charge to do the BIOS recovery, anyway, so don’t skip this first step.

Discharge (a.k.a. “flea power release”)

I’m not sure how critical this is, but several versions of Dell’s documentation told me to do it.

  1. Unscrew the bottom panel (with a T5 torx bit)
  2. Disconnect the internal battery cable
  3. Hold the power button for 30 secs

Yes, you will look like a fool doing this with the laptop propped up on its display so you can reach things. Next:

  1. Important! Keep the laptop display open until told otherwise! The XPS 13 9310 (and probably newer) power on when the display is opened, which will undo your hard work

  2. Re-connect the internal battery cable

  3. Carefully snap the bottom panel on—I’m not 100% sure this is needed, but I think it is because there’s a hardware tamper switch that tells the computer when the bottom panel is off

Remember to keep the display open this whole time, too—I know, it’s a pain.

Download the Latest BIOS Version

  1. Search Dell’s site for your model and find the latest BIOS file; for my XPS 13 9310 (not 2-in-1), it’s here.

    Don’t just Google for the model/BIOS, because Dell’s support site has terrible SEO/tagging. Instead, head to the Dell website, go to the support section for drivers and downloads, and search for your specific serial number/model to find the very latest BIOS version.

  2. Download the latest BIOS file in the Recovery Image (.rcv) format if offered, otherwise rename .exe to BIOS_IMG.rcv.

  3. Format a USB flash drive as FAT32, then drop the BIOS file to the root of the drive. You’ll also want a USB-C to USB-A adapter handy (unless you’re using a fancy USB-C flash drive).

Recover the BIOS

Important! If you can’t get this step to work, repeat the previous step, trying with a different flash drive.

  1. While keeping the laptop powered off, plug in your flash drive; again, I’m not sure how much this matters, but I seemed to only have success when using the right-hand USB port (near the power button) for the flash drive—it could just be a coincidence, but it seems to be the case for me

  2. While still keeping the laptop powered off, hold the Ctrl+Esc keys on the keyboard

  3. While still holding the keys, plug in your AC adapter (e.g. USB-C charger); once the Caps Lock key light lights up, release the keys

If all goes well, you should eventually get a BIOS recovery screen; it might reboot/flash a few times before getting to this screen, so be patient

Let me know on Mastodon if this worked for you, or if you have other tips. I still don’t know why I have to do this every once in a while, but it’s honestly making me reconsider Dells altogether. I really like the hardware, otherwise, but these sorts of issues have just been pretty common across models and years—I think for my next laptop, I’m eyeing that Star Labs StarFighter. 👀

May 27, 2024

cps in hoot

Good morning good morning! Today I have another article on the Hoot Scheme-to-Wasm compiler, this time on Hoot’s use of the continuation-passing-style (CPS) transformation.

calls calls calls

So, just a bit of context to start out: Hoot is a Guile, Guile is a Scheme, Scheme is a Lisp, one with “proper tail calls”: function calls are either in tail position, syntactically, in which case they are tail calls, or they are not in tail position, in which they are non-tail calls. A non-tail call suspends the calling function, putting the rest of it (the continuation) on some sort of stack, and will resume when the callee returns. Because non-tail calls push their continuation on a stack, we can call them push calls.

(define (f)
  ;; A push call to g, binding its first return value.
  (define x (g))
  ;; A tail call to h.
  (h x))

Usually the problem in implementing Scheme on other language run-times comes in tail calls, but WebAssembly supports them natively (except on JSC / Safari; should be coming at some point though). Hoot’s problem is the reverse: how to implement push calls?

The issue might seem trivial but it is not. Let me illustrate briefly by describing what Guile does natively (not compiled to WebAssembly). Firstly, note that I am discussing residual push calls, by which I mean to say that the optimizer might remove a push call in the source program via inlining: we are looking at those push calls that survive the optimizer. Secondly, note that native Guile manages its own stack instead of using the stack given to it by the OS; this allows for push-call recursion without arbitrary limits. It also lets Guile capture stack slices and rewind them, which is the fundamental building block we use to implement exception handling, Fibers and other forms of lightweight concurrency.

The straightforward function call will have an artificially limited total recursion depth in most WebAssembly implementations, meaning that many idiomatic uses of Guile will throw exceptions. Unpleasant, but perhaps we could stomach this tradeoff. The greater challenge is how to slice the stack. That I am aware of, there are three possible implementation strategies.

generic slicing

One possibility is that the platform provides a generic, powerful stack-capture primitive, which is what Guile does. The good news is that one day, the WebAssembly stack-switching proposal should provide this too. And in the meantime, the so-called JS Promise Integration (JSPI) proposal gets close: if you enter Wasm from JS via a function marked as async, and you call out to JavaScript to a function marked as async (i.e. returning a promise), then on that nested Wasm-to-JS call, the engine will suspend the continuation and resume it only when the returned promise settles (i.e. completes with a value or an exception). Each entry from JS to Wasm via an async function allocates a fresh stack, so I understand you can have multiple pending promises, and thus multiple wasm coroutines in progress. It gets a little gnarly if you want to control when you wait, for example if you might want to wait on multiple promises; in that case you might not actually mark promise-returning functions as async, and instead import an async-marked async function waitFor(p) { return await p} or so, allowing you to use Promise.race and friends. The main problem though is that JSPI is only for JavaScript. Also, its stack sizes are even smaller than the the default stack size.

instrumented slicing

So much for generic solutions. There is another option, to still use push calls from the target machine (WebAssembly), but to transform each function to allow it to suspend and resume. This is what I think of as Joe Marshall’s stack trick (also see §4.2 of the associated paper). The idea is that although there is no primitive to read the whole stack, each frame can access its own state. If you insert a try/catch around each push call, the catch handler can access local state for activations of that function. You can slice a stack by throwing a SaveContinuation exception, in which each frame’s catch handler saves its state and re-throws. And if we want to avoid exceptions, we can use checked returns as Asyncify does.

I never understood, though, how you resume a frame. The Generalized Stack Inspection paper would seem to indicate that you need the transformation to introduce a function to run “the rest of the frame” at each push call, which becomes the Invoke virtual method on the reified frame object. To avoid code duplication you would have to make normal execution flow run these Invoke snippets as well, and that might undo much of the advantages. I understand the implementation that Joe Marshall was working on was an interpreter, though, which bounds the number of sites needing such a transformation.

cps transformation

The third option is a continuation-passing-style transformation. A CPS transform results in a program whose procedures “return” by tail-calling their “continuations”, which themselves are procedures. Taking our previous example, a naïve CPS transformation would reify the following program:

(define (f' k)
  (g' (lambda (x) (h' k x))))

Here f' (“f-prime”) receives its continuation as an argument. We call g', for whose continuation argument we pass a closure. That closure is the return continuation of g, binding a name to its result, and then tail-calls h with respect to f. We know their continuations are the same because it is the same binding, k.

Unfortunately we can’t really slice abitrary ranges of a stack with the naïve CPS transformation: we can only capture the entire continuation, and can’t really inspect its structure. There is also no way to compose a captured continuation with the current continuation. And, in a naïve transformation, we would be constantly creating lots of heap allocation for these continuation closures; a push call effectively pushes a frame onto the heap as a closure, as we did above for g'.

There is also the question of when to perform the CPS transform; most optimizing compilers would like a large first-order graph to work on, which is out of step with the way CPS transformation breaks functions into many parts. Still, there is a nugget of wisdom here. What if we preserve the conventional compiler IR for most of the pipeline, and only perform the CPS transformation at the end? In that way we can have nice SSA-style optimizations. And, for return continuations of push calls, what if instead of allocating a closure, we save the continuation data on an explicit stack. As Andrew Kennedy notes, closures introduced by the CPS transform follow a stack discipline, so this seems promising; we would have:

(define (f'' k)
  (push! k)
  (push! h'')
  (g'' (lambda (x)
         (define h'' (pop!))
         (define k (pop!))
         (h'' k x))))

The explicit stack allows for generic slicing, which makes it a win for implementing delimited continuations.

hoot and cps

Hoot takes the CPS transformation approach with stack-allocated return closures. In fact, Hoot goes a little farther, too far probably:

(define (f''')
  (push! k)
  (push! h''')
  (push! (lambda (x)
           (define h'' (pop!))
           (define k (pop!))
           (h'' k x)))

Here instead of passing the continuation as an argument, we pass it on the stack of saved values. Returning pops off from that stack; for example, (lambda () 42) would transform as (lambda () ((pop!) 42)). But some day I should go back and fix it to pass the continuation as an argument, to avoid excess stack traffic for leaf function calls.

There are some gnarly details though, which I know you are here for!


For our function f, we had to break it into two pieces: the part before the push-call to g and the part after. If we had two successive push-calls, we would instead split into three parts. In general, each push-call introduces a split; let us use the term tails for the components produced by a split. (You could also call them continuations.) How many tails will a function have? Well, one for the entry, one for each push call, and one any time control-flow merges between two tails. This is a fixpoint problem, given that the input IR is a graph. (There is also some special logic for call-with-prompt but that is too much detail for even this post.)

where to save the variables

Guile is a dynamically-typed language, having a uniform SCM representation for every value. However in the compiler and run-time we can often unbox some values, generally as u64/s64/f64 values, but also raw pointers of some specific types, some GC-managed and some not. In native Guile, we can just splat all of these data members into 64-bit stack slots and rely on the compiler to emit stack maps to determine whether a given slot is a double or a tagged heap object reference or what. In WebAssembly though there is no sum type, and no place we can put either a u64 or a (ref eq) value. So we have not one stack but three (!) stacks: one for numeric values, implemented using a Wasm memory; one for (ref eq) values, using a table; and one for return continuations, because the func type hierarchy is disjoin from eq. It’s.... it’s gross? It’s gross.

what variables to save

Before a push-call, you save any local variables that will be live after the call. This is also a flow analysis problem. You can leave off constants, and instead reify them anew in the tail continuation.

I realized, though, that we have some pessimality related to stacked continuations. Consider:

(define (q x)
  (define y (f))
  (define z (f))
  (+ x y z))

Hoot’s CPS transform produces something like:

(define (q0 x)
  (save! x)
  (save! q1)

(define (q1 y)
  (restore! x)
  (save! x)
  (save! y)
  (save! q2)

(define (q2 z)
  (restore! x)
  (restore! y)
  ((pop!) (+ x y z)))

So q0 saved x, fine, indeed we need it later. But q1 didn’t need to restore x uselessly, only to save it again on q2‘s behalf. Really we should be applying a stack discipline for saved data within a function. Given that the source IR is a graph, this means another flow analysis problem, one that I haven’t thought about how to solve yet. I am not even sure if there is a solution in the literature, given that the SSA-like flow graphs plus tail calls / CPS is a somewhat niche combination.

calling conventions

The continuations introduced by CPS transformation have associated calling conventions: return continuations may have the generic varargs type, or the compiler may have concluded they have a fixed arity that doesn’t need checking. In any case, for a return, you call the return continuation with the returned values, and the return point then restores any live-in variables that were previously saved. But for a merge between tails, you can arrange to take the live-in variables directly as parameters; it is a direct call to a known continuation, rather than an indirect call to an unknown call site.

cps soup?

Guile’s intermediate representation is called CPS soup, and you might wonder what relationship that CPS has to this CPS. The answer is not much. The continuations in CPS soup are first-order; a term in one function cannot continue to a continuation in another function. (Inlining and contification can merge graphs from different functions, but the principle is the same.)

It might help to explain that it is the same relationship as it would be if Guile represented programs using SSA: the Hoot CPS transform runs at the back-end of Guile’s compilation pipeline, where closures representations have already been made explicit. The IR is still direct-style, just that syntactically speaking, every call in a transformed program is a tail call. We had to introduce save and restore primitives to implement the saved variable stack, and some other tweaks, but generally speaking, the Hoot CPS transform ensures the run-time all-tail-calls property rather than altering the compile-time language; a transformed program is still CPS soup.


Did we actually make the right call in going for a CPS transformation?

I don’t have good performance numbers at the moment, but from what I can see, the overhead introduced by CPS transformation can impose some penalties, even 10x penalties in some cases. But some results are quite good, improving over native Guile, so I can’t be categorical.

But really the question is, is the performance acceptable for the functionality, and there I think the answer is more clear: we have a port of Fibers that I am sure Spritely colleagues will be writing more about soon, we have good integration with JavaScript promises while not relying on JSPI or Asyncify or anything else, and we haven’t had to compromise in significant ways regarding the source language. So, for now, I am satisfied, and looking forward to experimenting with the stack slicing proposal as it becomes available.

Until next time, happy hooting!

May 24, 2024

hoot's wasm toolkit

Good morning! Today we continue our dive into the Hoot Scheme-to-WebAssembly compiler. Instead of talking about Scheme, let’s focus on WebAssembly, specifically the set of tools that we have built in Hoot to wrangle Wasm. I am peddling a thesis: if you compile to Wasm, probably you should write a low-level Wasm toolchain as well.

(Incidentally, some of this material was taken from a presentation I gave to the Wasm standardization organization back in October, which I think I haven’t shared yet in this space, so if you want some more context, have at it.)

naming things

Compilers are all about names: definitions of globals, types, local variables, and so on. An intermediate representation in a compiler is a graph of definitions and uses in which the edges are names, and the set of possible names is generally unbounded; compilers make more names when they see fit, for example when copying a subgraph via inlining, and remove names if they determine that a control or data-flow edge is not necessary. Having an unlimited set of names facilitates the graph transformation work that is the essence of a compiler.

Machines, though, generally deal with addresses, not names; one of the jobs of the compiler back-end is to tabulate the various names in a compilation unit, assigning them to addresses, for example when laying out an ELF binary. Some uses may refer to names from outside the current compilation unit, as when you use a function from the C library. The linker intervenes at the back-end to splice in definitions for dangling uses and applies the final assignment of names to addresses.

When targetting Wasm, consider what kinds of graph transformations you would like to make. You would probably like for the compiler to emit calls to functions from a low-level run-time library written in wasm. Those functions are probably going to pull in some additional definitions, such as globals, types, exception tags, and so on. Then once you have your full graph, you might want to lower it, somehow: for example, you choose to use the stringref string representation, but browsers don’t currently support it; you run a post-pass to lower to UTF-8 arrays, but then all your strings are not constant, meaning they can’t be used as global initializers; so you run another post-pass to initialize globals in order from the start function. You might want to make other global optimizations as well, for example to turn references to named locals into unnamed stack operands (not yet working :).

Anyway what I am getting at is that you need a representation for Wasm in your compiler, and that representation needs to be fairly complete. At the very minimum, you need a facility to transform that in-memory representation to the standard WebAssembly text format, which allows you to use a third-party assembler and linker such as Binaryen’s wasm-opt. But since you have to have the in-memory representation for your own back-end purposes, probably you also implement the names-to-addresses mapping that will allow you to output binary WebAssembly also. Also it could be that Binaryen doesn’t support something you want to do; for example Hoot uses block parameters, which are supported fine in browsers but not in Binaryen.

(I exaggerate a little; Binaryen is a more reasonable choice now than it was before the GC proposal was stabilised. But it has been useful to be able to control Hoot’s output, for example as the exception-handling proposal has evolved.)

one thing leads to another

Once you have a textual and binary writer, and an in-memory representation, perhaps you want to be able to read binaries as well; and perhaps you want to be able to read text. Reading the text format is a little annoying, but I had implemented it already in JavaScript a few years ago; and porting it to Scheme was a no-brainer, allowing me to easily author the run-time Wasm library as text.

And so now you have the beginnings of a full toolchain, built just out of necessity: reading, writing, in-memory construction and transformation. But how are you going to test the output? Are you going to require a browser? That’s gross. Node? Sure, we have to check against production Wasm engines, and that’s probably the easiest path to take; still, would be nice if this were optional. Wasmtime? But that doesn’t do GC.

No, of course not, you are a dirty little compilers developer, you are just going to implement a little wasm interpreter, aren’t you. Of course you are. That way you can build nice debugging tools to help you understand when things go wrong. Hoot’s interpreter doesn’t pretend to be high-performance—it is not—but it is simple and it just works. Massive kudos to Spritely hacker David Thompson for implementing this. I think implementing a Wasm VM also had the pleasant side effect that David is now a Wasm expert; implementation is the best way to learn.

Finally, one more benefit of having a Wasm toolchain as part of the compiler: %inline-wasm. In my example from last time, I had this snippet that makes a new bytevector:

 '(func (param $len i32) (param $init i32)
    (result (ref eq))
     (i32.const 0)
     (array.new $raw-bytevector
                (local.get $init)
                (local.get $len))))
 len init)

%inline-wasm takes a literal as its first argument, which should parse as a Wasm function. Parsing guarantees that the wasm is syntactically valid, and allows the arity of the wasm to become apparent: we just read off the function’s type. Knowing the number of parameters and results is one thing, but we can do better, in that we also know their type, which we use for intentional types, requiring in this case that the parameters be exact integers which get wrapped to the signed i32 range. The resulting term is spliced into the CPS graph, can be analyzed for its side effects, and ultimately when written to the binary we replace each local reference in the Wasm with a reference of the appropriate local variable. All this is possible because we have the tools to work on Wasm itself.


Hoot’s Wasm toolchain is about 10K lines of code, and is fairly complete. I think it pays off for Hoot. If you are building a compiler targetting Wasm, consider budgetting for a 10K SLOC Wasm toolchain; you won’t regret it.

Next time, an article on Hoot’s use of CPS. Until then, happy hacking!

May 23, 2024

Crosswords 0.3.13: Side Quests

It’s time for another Crosswords release.

I’ll keep this update short and sweet. I had grand plans last cycle to work on the word data and I did work a little on it — just not in the way I intended. Instead, a number of new contributors showed up which sent me in a different direction. I’m always happy to get new contributors and wanted to make sure they had a good experience. It ended up being a fun set of side quests before returning to the main set of features in the editor.

Cursor behavior

New contributor Adam filed a series of absolutely fantastic bug reports about the cursor behavior in the game. Adam fixed a couple bugs himself, and then pointed out that undo/redo behavior is uniquely weird with crosswords. Unlike text boxes, cursors have a natural direction associated with them that matters for the flow of editing.

In a nutshell, when you undo a word you want the cursor to be restored at the same orientation as where it was at the start of the guess. On the other hand, when redoing a guess, you want the cursor to advance normally, which might be in a different place or orientation. It’s subtle, but is the kind of user touch that you would normally never notice. It just feels “clunky” without a fix. With all these changes, the cursor behavior feels a lot more natural.

Can you spot the difference?

Selections and Intersections

Another side quest was to change the Autofill dialog to operate in-place. I foolishly thought that this would be a relatively quick change, but it ended up being a lot more work than expected. I’ll spare the details, but along the way, I also had to add three more features as dependencies.

First, I’ve wanted a way to leave pencil markings for a long time. These would transient markings that show possibilities for a square without marking. We use it to show the results of the in-place autofill operation.

Autofilling a section of the in place selection. Potential grids are written in pencil.

Second I fixed an old bug that I’ve wanted to fix for a long time. Previously, the word list showed all possible words independently. Now it only shows words that show in both directions. As an example, in the grid below we don’t show “ACID — (80)”  in the Down list as that final “D” would mean the Across clue would have “WD” as its prefix.

The acid test. WD-40 isn’t in our dictionary

This required writing code to efficiently calculate the intersection of two lists. It sounds easy enough, but the key word here is “efficient”. While I’m sure the implementation could be improved, it’s fast enough for now for it to be used synchronously.

Finally, I was able to use the intersection function to optimize the autofill algorithm itself. It’s significantly faster also more correct than the previous implementation, which means that the resulting boards will be more usable. It still can’t do a full 15×15 grid in a reasonable time, but it can solve about 1/3 of a grid.


  • Federico and I are working with Pranjal as a GSOC student for the summer. He’s going to work on porting libipuz to rust, and we spent a good amount of time planning the approach for that as well as prepping the library.
  • Tanmay has continued to work on the acrostic generator as part of last summer’s GSoC project. I’m so proud of his continued efforts in this space. Check out his recent post!
  • Gwyneth showed up with support for UTF-8 embedding in puz files as well as support for loading .xd crossword files.
  • I updated our use of libadwaita widgets to the latest release, and enabled style settings per-cell in the editor.

Until next time!

Introducing the WebKit Container SDK

Developing WebKitGTK and WPE has always had challenges such as the amount of dependencies or it’s fairly complex C++ codebase which not all compiler versions handle well. To help with this we’ve made a new SDK to make it easier.

Current Solutions

There have always been multiple ways to build WebKit and its dependencies on your host however this was never a great developer experience. Only very specific hosts could be “supported”, you often had to build a large number of dependencies, and the end result wasn’t very reproducable for others.

The current solution used by default is a Flatpak based one. This was a big improvement for ease of use and excellent for reproducablity but it introduced many challenges doing development work. As it has a strict sandbox and provides read-only runtimes it was difficult to use complex tooling/IDEs or develop third party libraries in it.

The new SDK tries to take a middle ground between those two alternatives, isolating itself from the host to be somewhat reproducable, yet being a mutable environment to be flexible enough for a wide range of tools and workflows.

The WebKit Container SDK

At the core it is an Ubuntu OCI image with all of the dependencies and tooling needed to work on WebKit. On top of this we added some scripts to run/manage these containers with podman and aid in developing inside of the container. It’s intention is to be as simple as possible and not change traditional development workflows.

You can find the SDK and follow the quickstart guide on our GitHub: https://github.com/Igalia/webkit-container-sdk

The main requirements is that this only works on Linux with podman 4.0+ installed. For example Ubuntu 23.10+.

In the most simple case, once you clone https://github.com/Igalia/webkit-container-sdk.git, using the SDK can be a few commands:

source /your/path/to/webkit-container-sdk/register-sdk-on-host.sh
wkdev-create --create-home

From there you can use WebKit’s build scripts (./Tools/Scripts/build-webkit --gtk) or CMake. As mentioned before it is an Ubuntu installation so you can easily install your favorite tools directly like VSCode. We even provide a wkdev-setup-vscode script to automate that.

Advanced Usage


A workflow that some developers may not be familiar with is making use of entirely disposable development environments. Since these are isolated containers you can easily make two. This allows you to do work in parallel that would interfere with eachother while not worrying about it as well as being able to get back to a known good state easily:

wkdev-create --name=playground1
wkdev-create --name=playground2

podman rm playground1 # You would stop first if running.
wkdev-enter --name=playground2

Working on Dependencies

An important part of WebKit development is working on the dependencies of WebKit rather than itself, either for debugging or for new features. This can be difficult or error-prone with previous solutions. In order to make this easier we use a project called JHBuild which isn’t new but works well with containers and is a simple solution to work on our core dependencies.

Here is an example workflow working on GLib:

wkdev-create --name=glib
wkdev-enter --name=glib

# This will clone glib main, build, and install it for us. 
jhbuild build glib

# At this point you could simply test if a bug was fixed in a different versin of glib.
# We can also modify and debug glib directly. All of the projects are cloned into ~/checkout.
cd ~/checkout/glib

# Modify the source however you wish then install your new version.
jhbuild make

Remember that containers are isoated from each other so you can even have two terminals open with different builds of glib. This can also be used to test projects like Epiphany against your build of WebKit if you install it into the JHBUILD_PREFIX.

To Be Continued

In the next blog post I’ll document how to use VSCode inside of the SDK for debugging and development.

May 21, 2024

Python 3.13 Beta 1

Python 3.13 beta 1 is out, and I've been working on the openSUSE Tumbleweed package to get it ready for the release.

Installing python 3.13 beta 1 in Tumbleweed

If you are adventurous enough to want to test the python 3.13 and you are using openSUSE Tumbleweed, you can give it a try and install the current devel package:

# zypper addrepo -p 1000 https://download.opensuse.org/repositories/devel:languages:python:Factory/openSUSE_Tumbleweed/devel:languages:python:Factory.repo
# zypper refresh
# zypper install python313

What's new in Python 3.13

Python interpreter is pretty stable nowadays and it doesn't change too much to keep code compatible between versions, so if you are writing modern Python, your code should continue working whit this new version. But it's actively developed and new versions have cool new functionalities.

  1. New and improved interactive interpreter, colorized prompts, multiline editing with history preservation, interactive help with F1, history browsing with F2, paste mode with F3.
  2. A set of performance improvements.
  3. Removal of many deprecated modules: aifc, audioop, chunk, cgi, cgitb, crypt, imghdr, mailcap, msilib, nis, nntplib, ossaudiodev, pipes, sndhdr, spwd, sunau, telnetlib, uu, xdrlib, lib2to3.

Enabling Experimental JIT Compiler

The python 3.13 version will arrive with an experimental functionality to improve performance. We're building with the --enable-experimental-jit=yes-off so it's disabled by default but it can be enabled with a virtualenv before launching:

$ PYTHON_JIT=1 python3.13

Free-threaded CPython

The python 3.13 has another build option to disable the Global Interpreter Lock (--disable-gil), but we're not enabling it because in this case it's not possible to keep the same behavior. Building with disabled-gil will break compatibility.

In any case, maybe it's interesting to be able to provide another version of the interpreter with the GIL disabled, for specific cases where the performance is something critical, but that's something to evaluate.

We can think about having a python313-nogil package, but it's not something trivial to be able to have python313 and python313-nogil at the same time in the same system installation, so I'm not planning to work on that for now.

GSoC 2024: An Introductory Post

From Me to You

I’m Bharat Tyagi, a third-year Computer Science student. I enjoy exploring things which is probably why I am here, writing this post for you all :). I’ll be working on Workbench this summer with my mentors Sonny Piers and Lorenz Wildberg.

My Journey with Linux and GNOME

I stumbled upon Linux when my phone needed a revival and only Linux had drivers for it. I only extensively started using Ubuntu at the beginning of college, and since then it has been a fun journey. The terminal is beautiful and knowing your way around it I think is an essential part of the ecosystem.

GNOME had been with me all along (considering I used Ubuntu and then Fedora) but always in the shadows, until recently when one of my extensions stopped working because it needed to be compiled for a more updated version of GNOME. I went looking into Github repositories and got to know about this wonderful desktop environment. I always enjoyed my distros because of how easy they were to use. Currently, I have settled for Fedora as my main, and I am enjoying what it has to offer.

Let's dive into some of the good stuff

I’ll be working on three things inside of Workbench, the first being porting the existing demos to Vala (An object-oriented programming language built for GNOME developers).

Secondly, building a new Library for Workbench. As the Library grows bigger, the vertical stack of demos makes it harder to look for a specific demo. To amend this we will be working on a new design that will make it easier and faster for everyone to navigate and search through demos.

The final piece of this puzzle will be implementing a more optimized code search using sqlite (blazing fast searches on the way!)

To Conclude

I think if it weren’t for the wonderful community members helping me during my initial contributions with their insights, I wouldn’t have been able to learn and progress at all. Therefore, I’d love to give back and help as much as I can.

I am excited about GSoC and thankful to my mentors for the opportunity. I also appreciate your time to reach this far into the post. I’ll be targeting bi-weekly updates, stay tuned for those! Until then

Buh bye!

May 20, 2024

Fedora 40 Release Party in Prague

Last Friday I organized a Fedora 40 release party in Prague. A month ago I got a message from Karel Ziegler of Etnetera Core if we could do a Fedora release party in Prague again. Etnetera Core is a mid-sized company that does custom software development and uses Red Hat technologies. They have a really cool office in Prague which we used as a venue for release parties several times in pre-covid times.

We got a bit unlucky with the date this time. It was really terrible weather in Prague on Friday. It was pouring outside. Moreover the Ice Hockey World Championship is taking place in Prague now and the Czech team played against Austria at the time of the release party. These two things contributed to the less than expected attendance. But in the end roughly 15 people showed up.

A round table with Fedora swag.
Fedora swag for party attendees.

The talk part was really interesting. In the end it took almost 4 hours because there was a lot of discussion. The first talk was mine, traditionally on Fedora Workstation that switched to a long discussion about Distrobox vs Toolbx. As a result of that Luboš Kocman of SUSE got interested in Ptyxis saying that it’s something they may actually adopt, too.

Lukáš Kotek on stage.
Lukáš Kotek talking about his legacy computing machine.

The second talk was delivered by Lukáš Kotek who talked about building a retro-gaming machine based on Fedora and Atomic Pi. Several people asked us to provide his slides online, so here they are:

The third talk was delivered by Karel Ziegler who spoke on the new release of his favorite desktop environment – Plasma 6. The last talk was supposed to be delivered by Ondřej Kolín, but at the beginning of the party we were not sure if he’d make it because he was travelling from Berlin and was stuck in Friday traffic. The first three talks took so long due to interesting discussions that Ondřej arrived just on time for his talk.

He spoke about his experience building a simple app and distributing it on Flathub. This again started an interesting discussion about new and traditional models of Linux app distribution.

In the middle of the party we were joined by Andre Klapper, a long-time GNOME contributor living in Prague, and Keywan Tonekaboni, a German open source journalist who is currently on his holidays travelling on trains around the Czech Republic. We found out that we were taking the same train to Brno next day, so on Saturday we had another two hours for Linux software topics. 🙂

I’d like to thank the Fedora Project for sponsoring my travel to Prague to organize the event and also big thanks to Etnetera Core for providing just perfect venue for the party and sponsoring refreshment (They even had a beer tap!) and the party cake.

Fedora 40 cake
Fedora 40 cake.

May 19, 2024

Analysis of GNOME Foundation’s public economy: concerns and thoughts

Apart from Software Development, I also have an interest in governance and finances. Therefore, last July, I was quite happy to attend my first Annual General Meeting (AGM), taking place in  GUADEC in Riga. I was a bit surprised by the format, as I was expecting something closer to an assembly than to a presentation with a Q&A at the end. It was still interesting to witness, but I was even more shocked by the huge negative cash flow (difference between revenue and expenditures). With the numbers presented, the foundation had lost approximately 650 000 USD in the 2021 exercise, and 300 000 USD in the 2022 exercise. And nobody seemed worry about it. I would have expected that such difference would come consequence of a great investment aimed at improving the situation of the foundation long-term. However, nothing like that was part of the AGM. This left me thinking, and a bit worried about what was going on with the financials and organization of the foundation. After asking a member of the Board in private, and getting no satisfactory response, I started doing some investigations

Public information research

The GNOME Foundation (legally GNOME Foundation Inc) has the 501(c)3 status. It means it is tax exempt. As part of such status, the tax payments, economic status and whereabouts of the GNOME Foundation Inc are public. So I had some look at the tax filling declarations of the last years. These contain detailed information about income and expenses, net assets (e.g: money in bank accounts), retribution of the Board, Executive director, and key employees, amount of money spent on fulfilling the goals of the foundation, and lots of other things. Despite their wide goal, the tax fillings are not very hard to read, and it’s easy to learn how much money the  foundation made or spent. Looking at the details, I found several worrying things, like the fact that revenue and expenses in the Annual Report presented in the AGM did not match those in the tax reports, that most expenses were aggregated in sections that required no explanation, or that there were some explanations for expenses required but missing. So I moved on to open a confidential issue in the Board Team in gitlab expressing my concerns.

The answer mostly covered an explanation of the big deficits in the previous year (that would have been great to have in the Annual Report), but was otherwise generally disappointing. Most of my concerns (all of which are detailed below) were answered with nicely-written variations of: “that’s a small problem, we are aware of it and working on it”, or “this is not common practice and you can find unrelated information in X place”. It has been 6 months, a new tax statement and annual report are available, but problems persist. So I am sharing publicly my concerns with several goals:

  • Make these concerns available to the general GNOME community. Even though everything I am presenting comes from public sources, it is burdensome to research, and requires some level of experience with bureaucracy.
  • Show my interest about the topic, as I plan to present myself to the Board of Directors in the next elections. My goal is to become part of the Finance Committee to help improve in the transparency and efficiency of accounting.
  • Make the Board aware of my concerns (and hopefully show that others also share them), so things can be improved regardless of whether I get or don’t get elected for the board

Analysis of data and concerns

The first analysis I did some months ago was not very detailed, and quite manual. This time, I gather information in more detailed, and compiled it in an spread sheet that I made publicly available. All the numbers are taken from GNOME’s Annual Reports and from the Tax declarations available in Pro Publica. I am very happy to get those values reviewed, as there could always be mistakes. I am still fairly certain that small errors won’t change my concerns, since those are based on patterns and not on one-time problems. So to my concerns:

  • Non-matching values between reports and taxes: in the last 3 years, for revenue and income, only the revenue in presented for Fiscal Year 2021/2022 matches what is actually declared. For the rest, differences vary, but go up to close to 9%. I was told that some difference is expected (as these numbers are crafted a bit earlier than taxes), the Board had worked on it, and the last year (the only one with at least revenue matching) is certainly better. But there are still something like 18 000 USD of mismatch in expenses. For me, this is a clear sign, that something is going wrong with the accounting of the foundation, even if improved in the last year.
  • Non-matching values between reports from different years: each Annual Report contains not only the results for that year, but also from the previous one. However, numbers only match half of the time. This is still the case for the latest report in 2023, where suddenly 10 000 USD disappeared from 2022’s expenses, growing the difference from what was declared that year to 27 000 USD. This again shows accountability issues, as previous-years’ numbers should certainly not diverge even more from the tax declarations than initial numbers.
  • Impossibility to match tax declarations and Annual Reports: the way the annual reports are presented, makes it impossible to get a more detailed picture of how are expenses and revenue split. For example, more than 99% of the revenue in 2023 is grouped under a single tax category, while the previous year at least 3 where used. However, the split in the Annual Reports remains roughly the same. So either the accounting is wrong in one of those years, or the split of expenses for the Annual Report was crafted from different data sources. Another example is how “Staff” makes the greatest expense until it ceases to exist in the latest report. However, staff-related expenses in the taxes do not make up for the “Staff” expense in the repots. The chances are that part of that is due to subcontracting, and thus counted in “Fees for services, Other” in the taxes. Unfortunately that category has its own issues.
  • Missing information in the tax declaration: most remarkably, in the tax fillings of fiscal years 2020/2021 and 2021/2022, the category: “Fees for services, Other” represents more than 10% of the expense, which is clearly stated that it should be explained in a later part of the tax filling. However, it is not. I was told 6 months ago that might have to be with some problem with ProPublica not getting the data, and that they would try to fix it. But I was not provided with the information, and 6 months later the public tax fillings still have not been amended.
  • Lack of transparency on expenses:
    • First, in the last 2 tax fillings, more than 50% of expenses lay under “Other salaries and wages”, and “Fees for services, Other”. These fields do not provide enough transparency (maybe they would if the previous point was addressed), and means most of the expenses actually go unaccounted.
    • Second, in the Annual Reports. For the previous 2 years, the biggest expenses were by far “Staff”. There exists a website with the staff and their roles, but there is no clear explanation of which money goes to whom or why. This can be a great problem if some part of the community does not feel supported in its affairs by the foundation. Compare for example with Mastodon’s Annual Report, where everybody on a pay-slip of free-lancing is accounted and written down how much they earn. This is made worse since the current year’s Annual Report has completely removed that category in favor of others. Tax fillings (once available) will, however, provide more context if proper explanations regarding “Fees for services, Other” is finally available.
  • Different categories and reporting formats: the reporting format changed completely in 2021/2022 compared to previous years, and changed completely again this year. This is a severe issue for transparency, since continuously updating formats make it hard to compare between years (which as noted above, is useful!). One of course can understand that things need to be updated to improve things, but such drastic changes do not help with transparency.

There are certainly other small things that I noticed that caught my attention. However, I hope these examples are enough to get my point across. And there is no need to make this blog post even longer!


My main conclusion from the analysis is that the foundation accounting and decision-making regarding expenses has been sub-par in the last years. It is also a big issue that there is a huge lack in transparency regarding the economic status and decision-making of the foundation. I learned more about the economic status of the foundation by reading tax fillings than by reading Annual Reports. Unfortunately, opening an issue with the Board six months ago to share these concerns has not make it better. It could possibly be, that things are much better than they look from outside, but the lack of transparency is making it not appear as so. I hope that I can join the Finance Committee, and help address these issues in the short term!

Status update, 19/05/2024 – GNOME OS and more

Seems this is another of those months where I did enough stuff to merit two posts. (See Thursday’s post on async Rust). Sometimes you just can’t get out of doing work, no matter how you try. So here is part 2.

A few weeks ago I went to the USA for a week to meet a client team who I’ve been working with since late 2022. This was actually the first time I left Europe since 2016*. Its wild how a Euro is now pretty much equal value to a US dollar, but everything costs about double compared to Europe. It was fun though and good practice for another long trip to the Denver GUADEC in July.

* The UK is still part of Europe, it hasn’t physically moved, has it?

GNOME OS stuff

The GNOME OS project has at least 3 active maintainers and a busy Matrix room, which makes it fairly healthy as GNOME modules go. There’s no ongoing funding for maintenance though and everyone who contributes is doing so mostly as a volunteer — at least, as far as I’m aware. So there are plenty of plans and ideas for how it could develop, but many of them are incomplete and nobody has the free time to push them to completion.

We recently announced some exciting collaboration between Codethink, GNOME and the Sovereign Tech Fund. This stint of full time work will help complete several in-progress tasks. Particularly interesting to me is finishing the migration to systemd-sysupdate (issue 832), and creating a convenient developer workflow and supporting tooling (issue 819) so we can finally kill jhbuild. Plus, of course, making the openQA tests great again.

Getting to a point where the team could start work, took a lot of work, most of which isn’t visible to the outside world. Discussions go back at least to November 2023. Several people worked over months on scoping, estimates, contracts and resourcing the engineering team before any of the coding work started: Sonny Piers working to represent GNOME, and on the Codethink side, Jude Onyenegecha and Weyman Lo, along with Abderrahim Kitouni and Javier Jardón (who are really playing for both teams ;-).

I’m not working directly on the project, but I’m helping out where I can on the communications side. We have at least 3 IRC + Matrix channels where communication happens every day, each with a different subset of people and cocumentation is scattered all over the place. Some of the Codethink team are seasoned GNOME contributors, others are not, and the collaborative nature of the GNOME OS project – there is no “BDFL” figure who takes all the decisions – means it’s hard to get clear answers around how things should be implemented. Hopefully my efforts will mean we make the most of the time available.

You can read more about the current work here on the Codethink blog: GNOME OS and systemd-sysupdate, the team will hopefully be posting regular progress updates to This Week In GNOME, and Martín Abente Lahaye (who very recently joined the team on the Codethink side \o/) is opening public discussions around the next generation developer experience for GNOME modules – see the discussion here.

Tiny SPARQL, Twinql, Sqlite-SPARQL, etc.

We’re excited to welcome Demigod and Rachel to the GNOME community, working on a SPARQL web IDE as part of Google Summer of Code 2024.

Since this is going to hopefully shine a new light on the SPARQL database project, it seems like a good opportunity to start referring to it by a better name than “Tracker SPARQL”, even while we aren’t going to actually rename the whole API and release 4.0 any time soon.

There are a few name ideas already, the front runners being Tiny SPARQL or Twinql, which I still can’t quite decide which I prefer. The former is unique but rather utilitarian, while the latter is a nicer name but is already used by a few other (mostly abandoned) projects. Which do you prefer? Let me know in the comments..

Minilogues and Minifreaks

I picked up a couple of hardware synthesizers, the Minilogue XD and the Minifreak. I was happy for years with my OP-1 synth, but after 6 years of use it has so many faults to be unplayable, and replacing it would cost more than a second hand car, plus its a little too tiny for on-stage use.

The Minilogue XD is one of the only mainstream synths to have an open SDK for custom oscillators and effects, full respect to Korg for their forward thinking here … although their Linux tooling is a closed source binary with an critical bug that they won’t fix, so, still some way to go before they get 10/10 for openness.

The Minifreak, by contrast, has a terrible Windows-only firmware update system, which works so poorly that I already had to the return the synth once to Arturia after a firmware update caused it to brick itself. There’s a stark lesson here in having open protocols which hopefully Arturia can pick up on. This synth has absolutely incredible sound design capabilities though so I decided to keep it and just avoid ever updating the firmware.

Here’s a shot of the Minifreak next to another mini freak: