Christopher Baines <mail@cbaines.net> writes:

> Raghav Gururajan <rvgn@disroot.org> writes:
>
>> libvirt.libvirtError: Unable to read from
>> '/sys/fs/cgroup/unified/machine/cgroup.controllers': No such file or
>> directory
>
> So, I've experienced this too. Even though this is a cgroup thing, I'm
> pretty sure this isn't an issue with Linux.
>
> I've tried reverting the changes in [1], and that seems to solve the
> issue. Unfortunately, I don't have any insight in to what's different
> between the problematic 5.5.0 release, and the working 5.4.0 release.
>
> 1: 458fe419232844d2021608d20dcd8f6e095eb2b4
> https://git.savannah.gnu.org/cgit/guix.git/commit/?id=458fe419232844d2021608d20dcd8f6e095eb2b4

This bug is consistently reproducible.  I've found an upstream bug
report that is very similar to what we're seeing here, so I've left a
comment telling the libvirt maintainers that Guix is also seeing a
similar issue:

https://bugzilla.redhat.com/show_bug.cgi?id=1751120

In the meantime, should we revert to version 5.4.0 in Guix?  I'm not
sure if there are any security vulnerabilities between 5.4.0 and the
most recent release, but this bug is currently preventing me from
creating any VMs at all in Guix using virt-manager, which is pretty bad.

-- 
Chris