renato@snappy:~$ snap change 186
Status  Spawn                 Ready                 Summary
Undone  2016-11-16T11:54:03Z  2016-11-16T11:58:26Z  Stop snap "ubuntu-calendar-app" services
Done    2016-11-16T11:54:03Z  2016-11-16T11:58:26Z  Make snap "ubuntu-calendar-app" unavailable to the system
Error   2016-11-16T11:54:03Z  2016-11-16T11:58:26Z  Remove security profile for snap "ubuntu-calendar-app" (x1)
Done    2016-11-16T11:54:03Z  2016-11-16T11:58:26Z  Remove data for snap "ubuntu-calendar-app" (x1)
Hold    2016-11-16T11:54:03Z  2016-11-16T11:58:26Z  Remove snap "ubuntu-calendar-app" (x1) from the system
Hold    2016-11-16T11:54:03Z  2016-11-16T11:58:26Z  Discard interface connections for snap "ubuntu-calendar-app" (x1)

......................................................................
Remove security profile for snap "ubuntu-calendar-app" (x1)

2016-11-16T08:58:26-03:00 ERROR cannot find installed snap "ubuntu-calendar-app" at revision x1

......................................................................
Remove snap "ubuntu-calendar-app" (x1) from the system

2016-11-16T08:54:04-03:00 ERROR cannot remove snap file "ubuntu-calendar-app", will retry in 3 mins: umount: /snap/ubuntu-calendar-app/x1: not mounted
2016-11-16T08:57:04-03:00 ERROR cannot remove snap file "ubuntu-calendar-app", will retry in 3 mins: umount: /snap/ubuntu-calendar-app/x1: not mounted