[Pkg-libvirt-maintainers] Bug#983871: error: internal error: failed to get cgroup backend for 'pathOfController'

[Jonas Schäfer]

Dear maintainer, dear Dio Putra,

I was hit by this too when upgrading LXC-heavy machines to Debian stable. The 
patch proposed by Dio Putra [1] fixes the issue for me (I built libvirt 7.0.0-3 
from salsa with that patch applied). The only caveat I found was that if you 
previously tried to destroy an LXC domain with unpatched 7.0.0-3, the destroy 
would still fail with this patch, but with a different error message:

error: Failed to destroy domain 'router'
error: Unable to read from '/sys/fs/cgroup/machine.slice/machine-
lxc\x2d1207\x2drouter.scope/cgroup.controllers': No such file or directory

I do consider this a lesser issue with the patch, given that without the 
patch, destroy won't ever work. A reboot rectifies the situation (restart of 
libvirtd does not seem to suffice). If the domain has not been attempted to be 
destroyed with 7.0.0-3, a destroy works flawlessly after upgrading to the 
patched version.

Please apply the patch and provide an update to Debian stable, as this breaks 
the libvirt-lxc usecase heavily.

kind regards,
Jonas

   [1]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=983871#30