[Pkg-xen-devel] Bug#921187: Getting rid of rdepends on libxenmisc4.X so we can do backports

[Hans van Kranenburg]

Package: src:xen
Version: 4.11.1-1

Currently, these are rdepends:

-$ apt-cache rdepends libxenmisc4.11
libxenmisc4.11
Reverse Depends:
  libxen-dev
  xen-utils-4.11
  collectd
  qemu-system-x86
  libvirt-daemon
  collectd-core

It's on the wishlist to start doing buster-backports for Xen.

If the user has a cluster of servers and can make use of live migrate,
then this allows the user to keep rolling-upgrading and following new
Xen releases without domU mass-reboots and downtime. Live migration is
only supported from N to N+1 versions, so e.g. from 4.10 to 4.11, but
not e.g. from 4.4 to 4.10.

The qemu one here is the most important/urgent one. Having this
dependency means that users of backports cannot use HVM, or that there
also need to be qemu backports.

When redoing the packaging in Q3 2018, all libraries with upstream
stable ABI were split off into packages with its own version number,
like libxendevicemodel1, libxenevtchn1, etc.

We think there's technically no reason that qemu has to depend on
libxenmisc4.11, so maybe it's the shlibs machinery that is confused.

Task here: find out why this is happening and see if the dependency can
be removed.

Apparently collectd and libvirt have a similar problem.