[systemd-devel] systemctl isolate "foo.service" expands to "foo.service.target"

[Chris Atkinson]

How does this interact with snapshots? While I was looking at man
systemctl it seems that one uses isolate to restore to a previous
snapshot:

   Snapshot Commands
       snapshot [NAME]
           Create a snapshot. If a snapshot name is specified, the new
   snapshot will be named after it. If none is specified, an automatic
   snapshot name is generated. In either case, the snapshot name used
   is printed to standard output, unless --quiet is specified.

           A snapshot refers to a saved state of the systemd manager.
           It is implemented itself as a unit that is generated
           dynamically with this command and has dependencies on all
           units active at the time. At a later time, the user may
           return to this state by using the isolate command on the
           snapshot unit.

           Snapshots are only useful for saving and restoring which
           units are running or are stopped, they do not save/restore
           any other state. Snapshots are dynamic and lost on reboot.

I created a named snapshot:

$ sudo systemctl snapshot derpy
derpy.snapshot

I tried restoring the named snapshot, but the mandatory mangling
to .target got in the way:

$ sudo systemctl isolate derpy.snapshot
Failed to start derpy.snapshot.target: Operation refused, unit may not
be isolated.

Results were the same with an automatically named snapshot.

Did I misunderstand the man page and there's some other way to restore
a snapshot?

Thanks,