ubuntu@localhost:~$ sudo ./devtools.snap remove unity8-session
error: cannot remove "unity8-session": snap "unity8-session" has changes in progress
ubuntu@localhost:~$ sudo ./devtools.snap changes
ID   Status  Spawn                 Ready                 Summary
26   Done    2016-08-22T13:13:35Z  2016-08-22T13:13:56Z  Refresh "ubuntu-core" snap from "edge" channel
27   Done    2016-08-22T16:19:26Z  2016-08-22T16:19:27Z  Update kernel and core snap revisions
28   Undone  2016-08-22T21:06:13Z  2016-08-22T21:07:28Z  Remove "unity8-session" snap
29   Done    2016-08-22T21:07:31Z  2016-08-22T21:07:58Z  Remove "unity8-session" snap
30   Done    2016-08-22T21:28:32Z  2016-08-22T21:28:33Z  Remove "unity8-session" snap
31   Error   2016-08-22T21:29:02Z  2016-08-22T21:29:03Z  Install "unity8-session" snap from file "unity8-session_0_amd64.snap"
32   Done    2016-08-22T21:29:28Z  2016-08-22T21:29:33Z  Install "unity8-session" snap from file "unity8-session_0_amd64.snap"
33   Done    2016-08-23T05:13:50Z  2016-08-23T05:14:05Z  Refresh "ubuntu-core" snap
34   Done    2016-08-23T13:40:42Z  2016-08-23T14:32:40Z  Remove "unity8-session" snap

ubuntu@localhost:~$