Regression introduced by 801c920e95.
Since then, the btrfsSimple subtest of the installer VM test fails with:
Btrfs did not return a path for the subvolume at /
The reason for this is that the output for "btrfs subvol show" has
changed between version 4.8.2 and 4.13.1.
For example the output of "btrfs subvol show /" in version 4.8.2 was:
/ is toplevel subvolume
In version 4.13.1, the output now is the following and thus the regular
expressions used in nixos-generate-config.pl and install-grub.pl now
match (which results in the error mentioned above):
/
Name: <FS_TREE>
UUID: -
Parent UUID: -
Received UUID: -
Creation time: -
Subvolume ID: 5
Generation: 287270
Gen at creation: 0
Parent ID: 0
Top level ID: 0
Flags: -
Snapshot(s):
In order to fix this I've changed nixos-generate-config.pl and
install-grub.pl, because both use "btrfs subvol show" in a similar vein,
so the regex for parsing the output now doesn't match anymore whenever
the volume path is "/", which should result in the same behaviour as we
had with btrfs-progs version 4.8.2.
Tested against the btrfsSimple, btrfsSubvols and btrfsSubvolDefault
subtests of the installer VM test and they all succeed now.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>