Due to my circumstances, I might be perhaps interested in dogfooding a larger number of GNOME system/session components on a daily basis than the average.

So far, I have been using jhbuild to help me with this deed, mostly in the form of jhbuild make to selectively build projects out of their git tree. See, there’s a point in life where writing long-winded CLI commands stop making you feel smart and work the opposite way, jhbuild had a few advantages I liked:

• I could reset and rebuild build trees without having to remember project-specific meson args.
• The build dir did not pollute the source dir, and would be wiped out without any loss.
• The main command is pretty fast to type with minimal finger motion for something done so frequently, jh<tab>.

This, combined with my habit to use Fedora Rawhide also meant I did not require to rebuild the world to get up-to-date dependencies, keeping the number of miscellaneous modules built to a minimum.

This was all true even after Silverblue came around, and Florian unlocked the “run GNOME as built from toolbox” achievement. I adopted this methodology, but still using jhbuild to build things inside that toolbox, for the sake of convenience.

Enter sysext-utils

Meanwhile, systemd sysexts came around as a way to install “extensions” to the base install, even over atomic distributions, paving a way for development of system components to happen in these distributions. More recently Martín Abente brought an excellent set of utilities to ease building such sysexts.

This is a great step in the direction towards sysexts as a developer testing method. However, there is a big drawback for users of atomic distributions: to build these sysexts you must have all necessary build dependencies in your host system. Basically, desecrating your small and lean atomic install with tens to hundreds of packages. While for GNOME OS it may be true that it comes “with batteries included”, feels like a very big margin to miss the point with Silverblue, where the base install is minimal and you are supposed to carry development with toolbox, install apps with flatpak, etc etc.

What is necessary

Ideally, in these systems, we’d want:

1. A toolbox matching the version of the host system.
2. With all development tools and dependencies installed
3. The sysexts to be created from inside the toolbox
4. The sysexts to be installed in the host system
5. But also, the installed sysexts need to be visible from inside the toolbox, so that we can build things depending on them

The most natural way to achieve both last points is building things so they install in /usr/local, as this will allow us to also mount this location from the host inside the toolbox, in order to build things that depend on our own sysexts.

And last, I want an easy way to manage these projects that does not get in the middle of things, is fast to type, etc.

Introducing gg

So I’ve made a small script to help myself on these tasks. It can be installed at ~/.local/bin along with sysext-utils, and be used in a host shell to generate, install and generally manage a number of sysexts.

Sysexts-utils is almost there for this, I however needed some local hacks to help me get by:

– Since I have these are installed at ~/.local, but they will be run with pkexec to do things as root, the python library lookup paths had to be altered in the executable scripts (sysext-utils#10).
– They are ATM somewhat implicitly prepared to always install things at /usr, I had to alter paths in code to e.g. generate GSettings schemas at the right location (sysext-utils#11).

Hopefully these will be eventually sorted out. But with this I got 1) a pristine atomic setup and 2) My tooling in ~/.local 3) all the development environment in my home dir, 4) a simple and fast way to manage a number of projects. Just most I ever wanted from jhbuild.

This tool is a hack to put things together, done mainly so it’s intuitive and easy to myself. So far been using it for a week with few regrets except the frequent password prompts. If you think it’s useful for you too, you’re welcome.