On Tue, 21 Oct 2014 16:50:59 +0200, Michal Schmidt said:

> Suddenly? CONFIG_CGROUPS was systemd's requirement from its very
> beginning. It used to print:
>
>    Failed to mount /sys/fs/cgroup: No such file or directory.
>
> and stop booting at this point.

Actually, no. It *wasn't* there from "its very beginning".

See Fedora bug https://bugzilla.redhat.com/show_bug.cgi?id=628004

There was a period of time when it did *NOT* print that message and give
you a hint of what was wrong.

And an indicator of the problems with the systemd design team mentality
is that the comment was "be nice to Ingo Molnar", rather than admitting
that yes, printing that the kernel didn't have a required feature might
be a good idea....

(Yes, I personally got bit by this one myself...)