On Sat, 8 Aug 2015 at 18:23 Chris Samuel <chris@csamuel.org> wrote:
I don't think this is related to helping Brian with his query about why his
laptop won't sleep when he shuts its lid.

Getting back on topic, I reported it as a Debian bug:

http://bugs.debian.org/794744

They referred me to this bug:

https://github.com/systemd/systemd/issues/451
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=788400#92

Unfortunately, while I am clearly affected by this bug - which looks like a kernel bug to me with a work around in latest versions of systemd, it doesn't explain why suspend won't work after a reboot.

I also found I can manually force suspend without sudo:

systemctl suspend

Still, might be worth trying the latest version of systemd and seeing if it does help or not. At the very least I might get more debugging information.