Vincent Lefevre:
[...]
In any case, reloading daemons during the upgrade process is current
buggy as this can yield a race for the dpkg frontend lock:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1070027
Depending on which gets the lock first:
* This can make (at least) aptitude fail, leaving the system
in an inconsistent state.
* This can make the apt.systemd.daily script fail.
Ok. There is not much we can do on the debhelper side of this. The
systemd maintainers and the apt or/and aptitude maintainers maybe with
the dpkg maintainers having a combined huddle here might be more productive.
Once they have figured out the solution, this might trigger a change to
debhelper.
Best regards,
Niels
