We have had some discussion on the bugzilla entry for this bug [1].
So, just to make sure all of us are on the same page, as opposed to my first
plan to implement a "--force" switch, the forced provisioning will always
be the default. Thus, bkr machine-test system1.fqdn.name will provision the system
even if it is manual or broken.
[1]
https://bugzilla.redhat.com/show_bug.cgi?id=1093224