For a lot of the work the non-interactive drivers are enough and it is
probably a good idea to keep it accessible for debugging without
touching the Nix expression.
Since we previously stripped down the features of `qemu_test` some of
the features users are used to while running tests through the (impure)
driver didn't work anymore. Most notably we lost support for graphical
output and audio. With this change the `driver` attribute uses are more
feature complete version of QEmu compared to the one used in the pure
Nix builds.
This gives us the best of both worlds. Users are able to see the
graphical windows of VMs while CI and regular nix builds do not have to
download all the (unnecessary) dependencies.
Since using flakes disallows the usage of <unstable> (which I use in
some tests), this adds an alternative. By setting specialArgs, all VMs
can get the `unstable` flake input as an arg. This is not possible with
extraConfigurations, as that would lead to infinite recursions.
This completes the removal of the nested log feature, which previously
got removed from Nix, Hydra, stdenv and GNU Make. In particular, this
means that the output of VM builds no longer contains a copy of
jQuery.
While it's a good idea to automate the linting of the python code used
for our tests, I think that it can be quite distracting when hacking on
a NixOS test.
I figured that it might be more convenient to add an option as a
shortcut for this to avoid that everyone needs to dig into the test
driver again.
The upstream session files display managers use have no concept of sessions being composed from
desktop manager and window manager. To be able to set upstream session files as default
session, we need a single option. Having two different ways to set default session would be confusing,
though, so we decided to deprecate the old method.
We also created separate script for each session, just like we already had a separate desktop
file for each one, and started using displayManager.sessionPackages mechanism to make the
session handling more uniform.
The SLIM project is abandoned and their last release was in 2013.
Because of this it poses a security risk to systems, no one is working
on it or picked up maintenance. It also lacks compatibility with systemd
and logind sessions. For users, there liikely isn't anything like slim
that's as lightweight in terms of dependencies.