In the puppet class mediawiki::cgroup (defined in modules/mediawiki/manifests/cgroup.pp, and then called by modules/profile/manifests/mediawiki/common.pp), ensure_packages('cgroup-bin') is called — on Debian 11 (Bullseye), this package appears to have been replaced by cgroup-tools and the transitional package removed.
Error: Execution of '/usr/bin/apt-get -q -y -o DPkg::Options::=--force-confold install cgroup-bin' returned 100: Reading package lists... Building dependency tree... Reading state information... Package cgroup-bin is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source However the following packages replace it: cgroup-tools E: Package 'cgroup-bin' has no installation candidate Error: /Stage[main]/Mediawiki::Cgroup/Package[cgroup-bin]/ensure: change from 'purged' to 'present' failed
Doing a sudo apt search cgroup-* on Debian 10 gives you:
cgroup-bin/oldstable 0.41-8.1 all control and monitor control groups (transitional package) cgroup-tools/oldstable 0.41-8.1 amd64 control and monitor control groups (tools)
whereas on 11 you only get
cgroup-tools/stable 0.41-11 amd64 control and monitor control groups (tools)
I'm going to submit a patch which will check for if the distro "codename" is Bullseye, i.e.
if debian::codename::eq('bullseye') { ensure_packages('cgroup-tools') } else { ensure_packages('cgroup-bin') }