Comment 7 for bug 1631514

Manually install snapd_2.17.1_amd64.deb then upgrade to 2.20.1ubuntu1 cannot reproduce this.

snapd ran properly:
Jan 12 12:09:02 X230 /usr/lib/snapd/snapd[11593]: daemon.go:207: DEBUG: init done in 831.812µs
Jan 12 12:09:11 X230 /usr/lib/snapd/snapd[11593]: daemon.go:172: DEBUG: uid=0;@ POST /v2/snaps 9.05233594s 202
Jan 12 12:09:29 X230 /usr/lib/snapd/snapd[11593]: daemon.go:172: DEBUG: uid=1000;@ GET /v2/snaps 7.988072ms 200
Jan 12 12:09:32 X230 /usr/lib/snapd/snapd[11593]: daemon.go:172: DEBUG: uid=1000;@ GET /v2/interfaces 2.114854ms 200

But still seeing 'not starting it' in log messages:
Log started: 2017-01-12 12:08:55
Warning: Stopping snapd.service, but it can still be activated by:
  snapd.socket
Unpacking snapd (2.20.1ubuntu1) over (2.17.1) ...
Processing triggers for man-db (2.7.5-1) ...
Setting up snapd (2.20.1ubuntu1) ...
Installing new version of config file /etc/X11/Xsession.d/65snappy ...
snapd.service is a disabled or a static unit, not starting it.
Log ended: 2017-01-12 12:09:03