On Fri, 05 May 2023 at 23:11:54 +0100, Luca Boccassi wrote:
> In practice, I suspect that out of ~2000 packages shipping bin/ sbin/
> lib*/, only a small fraction would end up needing to further move
> files out to other packages
I think the most common case for this is likely to be systemd system
units, which are currently in /lib/systemd and are sometimes moved between
binary packages. Splitting out dbus-system-bus-common during the bookworm
release cycle is a recent example, but it also seems reasonably common
to move systemd units around as part of having a distinction between
"the ready-made system service" and "the binary you can run by hand"
(see apache2 vs. apache2-bin).
udev rules are in a similar situation: consumed by an important system
service, but shipped by any random package that wants to adjust its
behaviour.
Two things about systemd units make them a relatively difficult case
for distro-wide changes like this:
For /bin, /sbin and to a lesser extent /lib/TUPLE, we can often assume
that only "core" packages (whose maintainers should be paying attention to
subtleties like this) are affected by any change, because the historical
definition of those directories was "just enough to boot the system or
do disaster recovery", minimizing what should be there; but the number
of packages that touch /lib/systemd is rather large, and a lot of them
are leaf or near-leaf packages.
Also, they're managed (and sometimes installed) by debhelper, which
needs to be able to do the right thing relatively automatically. For
example, if maintainers need to be able to take some special action at
the point at which their /lib/systemd units move to /usr/lib/systemd,
then I think debhelper installing into /usr/lib/systemd would have to
be gated by a compat level change.
smcv
