Toolbx is a utility that empowers users and developers to install software on isolated environments, drastically reducing the risk of compromising the stability of their operating system. It is also indispensable for users of immutable distros (e.g. Fedora Silverblue, Endless OS, Vanilla OS, etc) like myself.

On this blog post I’ll share how I used toolbx to safely build and run GNOME Settings.

Step 0: backup all your settings

The isolation provided by toolbx only applies to system directories (those that you need sudo to make changes to). That means your $HOME directory is as vulnerable to mishaps as it is outside of the toolbx!

Since your preferences are stored within your $HOME directory make sure you back them up before meddling with an unstable version of the GNOME Settings app. To make the backup run:

dconf dump / > $HOME/preferences_backup.ini

Again, since your $HOME directory is not safer inside a toolbx, move that file somewhere else (e.g. a USB stick, a trusted cloud storage provider, etc). To restore the backup file, move it back to your $HOME directory and run:

dconf load -f / < $HOME/preferences_backup.ini

Step 1: choose the right toolbx image

To choose the operating system that will run on our toolbx, you need to pick its base image. To figure that out, take a look at the .gitlab-ci.yml:

.fedora.container.common:
  # ...
  tags: [ crun ]
  variables:
    # ...
    FDO_DISTRIBUTION_TAG: '2023-03-14.0-main'
    FDO_DISTRIBUTION_VERSION: rawhide

Looks like GNOME Settings is targetting Fedora Rawhide, which is a rolling build of Fedora that has the purpose of testing software for upcoming releases. That said, you can create your toolbx with the following command:

toolbox create gnome-control-center --image registry.fedoraproject.org/fedora-toolbox:rawhide

If you are doing this for the first time, this command will download the Fedora Rawhide toolbx image. It will take some time and some storage (500Mb) but don’t worry it’ll be worth it! Once the toolbx is created, enter it with:

toolbox enter gnome-control-center

Step 2: installing dependencies

To install the dependencies needed to build GNOME Settings, simply run:

sudo dnf builddep gnome-control-center

Step 3: building and running

Finally, head to the root of its repository and run:

make _build && ninja -C _build

This will build GNOME Settings at ./_build/shell/gnome-control-center.

Step 4: taking advantage of the isolation

To run the executable file, you can leave the toolbx and execute like so:

exit
./_build/shell/gnome-control-center

However, you may want to run it inside your toolbx! If that’s the case, you also have to install your local build of GNOME Settings. To do that, run:

ninja -C _build install

This will allow you to take advantage of the isolated environment provided by toolbx! For instance, when was writing this contribution to the applications panel, I wanted to test a few apps that I didn’t have (nor wanted to have) installed on my system. To address that, I installed a few applications inside my development toolbx! As you can see, the Settings app lists different applications when I open it from inside or from outside of the toolbx:

That’s all! Hope this was useful for you!

Credit

This post is a personal take on the GNOME Settings’ own guide on building with toolbx.