bug#59784: [version 1.4.0rc1] Retrying a failed install fails

[Ludovic Courtès]

Hi again,

Ludovic Courtès <ludo@gnu.org> skribis:

> It looks like the store is in a broken state, with its database not
> matching its actual contents.  The ‘install-system’ procedure is
> supposed to protect against that by making a backup of the database
> before starting the installation and restoring it afterwards.  (It
> apparently worked for me when I interrupted ‘guix system init’ by
> hitting C-c.)

Actually, look at the excerpt from final.scm:

         ;; Restart guix-daemon so that it does no keep the MNT namespace
         ;; alive.
         (restart-service 'guix-daemon)
         (copy-file saved-database database-file)

We’re restarting the daemon *before* we have restored the database,
which is wrong: depending on how lucky you are, guix-daemon might load
the old database (all this depends on what exactly happens when sqlite
opens the database, but I think there’s a possibility that it will load
or cache a few things and thus fail to see the changes ‘copy-file’
introduces.)

So my guess is that things will be much better if we swap these two
lines.

Florian, it would be great if you could try that and run a new image
generated version ‘version-1.4.0’ with these two lines changed.  To
produce the image, run:

  ./pre-inst-env guix system image -t iso9660 --label=Guix \
    gnu/system/install.scm

Ludo’.