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

[Thorsten Glaser]

Package: libvirt-daemon
Version: 7.0.0-2
Severity: important
X-Debbugs-Cc: tg at mirbsd.de

After an upgrade+reboot I cannot start VMs *again* with some cgroup error:

$ wirrsh start Netboot                                                                        
error: Failed to start domain 'Netboot'
error: internal error: failed to get cgroup backend for 'pathOfController'

To unconfuse:

$ alias wirrsh
wirrsh='virsh -c qemu:///system'

-- System Information:
Debian Release: bullseye/sid
  APT prefers unreleased
  APT policy: (500, 'unreleased'), (500, 'buildd-unstable'), (500, 'unstable'), (100, 'experimental')
Architecture: x32 (x86_64)
Foreign Architectures: i386, amd64

Kernel: Linux 5.10.0-3-amd64 (SMP w/4 CPU threads)
Kernel taint flags: TAINT_FIRMWARE_WORKAROUND
Locale: LANG=C, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /bin/lksh
Init: sysvinit (via /sbin/init)

Versions of packages libvirt-daemon depends on:
ii  libblkid1                   2.36.1-7
ii  libc6                       2.31-9
ii  libdevmapper1.02.1          2:1.02.175-2.1
ii  libgcc-s1                   10.2.1-6
ii  libglib2.0-0                2.66.7-1
ii  libnetcf1                   1:0.2.8-1.1
ii  libparted2                  3.4-1
ii  libpcap0.8                  1.10.0-2
ii  libpciaccess0               0.16-1
ii  libselinux1                 3.1-3
ii  libudev1                    247.3-1
ii  libvirt-daemon-driver-qemu  7.0.0-2
ii  libvirt0                    7.0.0-2
ii  libxml2                     2.9.10+dfsg-6.3+b1

Versions of packages libvirt-daemon recommends:
pn  libvirt-daemon-driver-lxc   <none>
pn  libvirt-daemon-driver-vbox  <none>
pn  libvirt-daemon-driver-xen   <none>
ii  libxml2-utils               2.9.10+dfsg-6.3+b1
ii  netcat-openbsd              1.217-3
ii  qemu-system                 1:5.2+dfsg-6

Versions of packages libvirt-daemon suggests:
pn  libvirt-daemon-driver-storage-gluster       <none>
pn  libvirt-daemon-driver-storage-iscsi-direct  <none>
pn  libvirt-daemon-driver-storage-rbd           <none>
pn  libvirt-daemon-driver-storage-zfs           <none>
ii  libvirt-daemon-system                       7.0.0-2
pn  numad                                       <none>

-- no debconf information