minifai: fallback to debian-archive-keyring

[crpb]

• if GRML_FAI_CONFIG isn't in the same tree-depth as the original the relative links in buildstrap-keyring (blame debhelper!) will not be resolveable which makes mmdebstrap fail with keyring=None.

[zeha]

imo the right thing to do is to fail early in this case. papering over a file not found issue seems icky

[zeha]

If someone provides a short reproducer, I can try to take a closer look.

[mika]

Friendly ping /cc @youam - would appreciate your feedback here also!

[youam]

Hey there. Thanks @mika for the nudge; otherwise this would've stayed on my todo-list for a while..

Reproducing this bug is really simple. Boot a fresh grml-full Nudlaug, prepare with the following steps:

cd /mnt
rsync -a /usr/share/grml-live ./
echo GRML_FAI_CONFIG=/mnt/grml-live/config > /etc/grml/grml-live.local

and grml-live will fail in the mmdebstrap step

[crpb]

yeah, like that or via overlay so you don't have to update/merge the whole tree every time.
/etc/fstab

overlay /grml/config overlay x-systemd.automount,x-systemd.mount-timeout=10,x-systemd.idle-timeout=30,lowerdir=/usr/share/grml-live/config,upperdir=/grml/overlay/local,workdir=/grml/overlay/work 0 2