If ostree is run in a test setup where it operates as root in a tmp
directory, it might cause issues to flag the deployments as immutable.
The test harness might simply be doing an `rm -rf` (effectively the case
for gnome-desktop-testing-runner), which will then fail.
We add a new debug option to the ostree_sysroot object using GLib's
GDebugKey functionality to allow our tests to communicate to ostree that
we don't want immutable deployments.
The logic for checking which bootversion to use tries to access
sysroot->bootversion if the user didn't specify an explicit bootversion
on the command-line nor through the env var. However, at that point, the
sysroot object is not yet initialized, so it will always return 0, even
when it's 1.
This would cause e.g. `grub2-mkconfig` to have no output for the BLS
entries whenever the entries were under `/boot/loader.1`.
Related: RHBZ1293986
Jonathan Lebon