I have no swap here, so suspend is possible, but not hibernation.

$ gdbus call --system --dest org.freedesktop.login1 --object-path /org/freedesktop/login1 --method org.freedesktop.login1.Manager.CanSuspend
('challenge',)
$ gdbus call --system --dest org.freedesktop.login1 --object-path /org/freedesktop/login1 --method org.freedesktop.login1.Manager.CanHibernate
('na',)

$ sudo swapon -av
$ gdbus call --system --dest org.freedesktop.login1 --object-path /org/freedesktop/login1 --method org.freedesktop.login1.Manager.CanHibernate
('challenge',)

$ sudo gdbus call --system --dest org.freedesktop.login1 --object-path /org/freedesktop/login1 --method org.freedesktop.login1.Manager.CanHibernate
('yes',)

Quoting http://freedesktop.org/wiki/Software/systemd/logind/: "If "na" is returned the operation is not available because hardware, kernel or drivers do not support it."

I see no bug here. I'm closing this, because the code looks correct and rather straightforward. If you have a specific example where this doesn't work (with recent git), please reopen with some more details.

I get

$ gdbus call --system --dest org.freedesktop.login1 --object-path /org/freedesktop/login1 --method org.freedesktop.login1.Manager.CanHibernate
('yes',)

even though I have no swap:

$ cat /proc/swaps 
Filename                                Type            Size    Used    Priority

This is with systemd 204 on Debian testing.
Please tell me which other details you need.

(In reply to comment #2)
>> ... with recent git ...
> This is with systemd 204 on Debian testing.
Sorry, 204 is ancient history for the upstream bug tracker. With a bit of luck http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=727708 will be resolved soon and Debian can move to something more recent.

I see. I'll re-test this when/if Debian has a more recent version, and report my findings here. Thanks for your replies.