Am 10.08.2017 12:33, schrieb justus-...@piater.name:
I keep running into problems caused by stale installations from the
such as upgraded, ABI-incompatible dependencies or Python packages
installed under /usr/lib/python3.5/ where they are no longer found
the move to python3.6.
My understanding is that in such situations, the affected packages
should bump pkgrel to force rebuild and reinstall, even if the source
and the rest of the PKGBUILD remain unchanged.
Is this understanding correct? If so, can this be clarified in places
such as  where people cannot miss it?
Confronted with this issue, some maintainers advise their users to just
rebuild by hand, but that defeats part of the purpose of package
management systems. I don't want to have to debug weird run-time
one by one, trace the problem to this trivial issue, and then solve
of them by manual rebuild.
in my opinion, pkgrel is to be bumped when something with regard to the
package changes, not for the sake of rebuild only.
Keeping track of rebuilds is the users task, you could e.g. after a
python update go through all remaining files in the old versions folder
and initiate a rebuild of the corresponding packages.
This is easily scriptable and should be regarded as usual update hygiene
like ocassionally checking /var/cache/pacman and other tasks.
Arch is not about fully automating everything and hiding the internal
workings from the user.
About the debugging: when a major update happens, you are usually
informed about the necessary actions in the pacman output. Paying
attention to that is not optional in Arch.