Comment 25 for bug 1796137

Some more details about what's happening inside snapd:

$ snap changes --abs-time
ID Status Spawn Ready Summary
1 Done 2018-10-09T20:35:36Z 2018-10-09T20:35:47Z Initialize system state
2 Done 2018-10-09T20:35:36Z 2018-10-09T20:35:38Z Initialize device

$ snap change --abs-time 1
Status Spawn Ready Summary
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:36Z Ensure prerequisites for "core" are available
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:36Z Prepare snap "/var/lib/snapd/seed/snaps/core_5548.snap" (5548)
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:37Z Mount snap "core" (5548)
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:37Z Copy snap "core" data
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:38Z Setup snap "core" (5548) security profiles
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:38Z Make snap "core" (5548) available to the system
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:39Z Automatically connect eligible plugs and slots of snap "core"
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:39Z Set automatic aliases for snap "core"
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:39Z Setup snap "core" aliases
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:39Z Run install hook of "core" snap if present
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:39Z Start snap "core" (5548) services
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:39Z Run configure hook of "core" snap if present
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:39Z Ensure prerequisites for "lxd" are available
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:39Z Prepare snap "/var/lib/snapd/seed/snaps/lxd_9010.snap" (9010)
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:39Z Mount snap "lxd" (9010)
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:39Z Copy snap "lxd" data
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:40Z Setup snap "lxd" (9010) security profiles
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:40Z Make snap "lxd" (9010) available to the system
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:41Z Automatically connect eligible plugs and slots of snap "lxd"
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:44Z Set automatic aliases for snap "lxd"
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:44Z Setup snap "lxd" aliases
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:44Z Run install hook of "lxd" snap if present
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:45Z Start snap "lxd" (9010) services
Done 2018-10-09T20:35:35Z 2018-10-09T20:35:45Z Run configure hook of "lxd" snap if present
Done 2018-10-09T20:35:36Z 2018-10-09T20:35:45Z Ensure prerequisites for "google-cloud-sdk" are available
Done 2018-10-09T20:35:36Z 2018-10-09T20:35:45Z Prepare snap "/var/lib/snapd/seed/snaps/google-cloud-sdk_55.snap" (55)
Done 2018-10-09T20:35:36Z 2018-10-09T20:35:46Z Mount snap "google-cloud-sdk" (55)
Done 2018-10-09T20:35:36Z 2018-10-09T20:35:46Z Copy snap "google-cloud-sdk" data
Done 2018-10-09T20:35:36Z 2018-10-09T20:35:46Z Setup snap "google-cloud-sdk" (55) security profiles
Done 2018-10-09T20:35:36Z 2018-10-09T20:35:46Z Make snap "google-cloud-sdk" (55) available to the system
Done 2018-10-09T20:35:36Z 2018-10-09T20:35:46Z Automatically connect eligible plugs and slots of snap "google-cloud-sdk"
Done 2018-10-09T20:35:36Z 2018-10-09T20:35:46Z Set automatic aliases for snap "google-cloud-sdk"
Done 2018-10-09T20:35:36Z 2018-10-09T20:35:46Z Setup snap "google-cloud-sdk" aliases
Done 2018-10-09T20:35:36Z 2018-10-09T20:35:46Z Run install hook of "google-cloud-sdk" snap if present
Done 2018-10-09T20:35:36Z 2018-10-09T20:35:47Z Start snap "google-cloud-sdk" (55) services
Done 2018-10-09T20:35:36Z 2018-10-09T20:35:47Z Run configure hook of "google-cloud-sdk" snap if present
Done 2018-10-09T20:35:33Z 2018-10-09T20:35:47Z Mark system seeded
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:41Z Run hook prepare-plug-lxd-support of snap "lxd"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:41Z Run hook prepare-slot-lxd-support of snap "core"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:42Z Connect lxd:lxd-support to core:lxd-support
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:42Z Run hook connect-slot-lxd-support of snap "core"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:42Z Run hook connect-plug-lxd-support of snap "lxd"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:41Z Run hook prepare-plug-network of snap "lxd"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:41Z Run hook prepare-slot-network of snap "core"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:42Z Connect lxd:network to core:network
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:42Z Run hook connect-slot-network of snap "core"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:42Z Run hook connect-plug-network of snap "lxd"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:41Z Run hook prepare-plug-network-bind of snap "lxd"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:41Z Run hook prepare-slot-network-bind of snap "core"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:44Z Connect lxd:network-bind to core:network-bind
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:44Z Run hook connect-slot-network-bind of snap "core"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:44Z Run hook connect-plug-network-bind of snap "lxd"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:41Z Run hook prepare-plug-system-observe of snap "lxd"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:41Z Run hook prepare-slot-system-observe of snap "core"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:43Z Connect lxd:system-observe to core:system-observe
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:43Z Run hook connect-slot-system-observe of snap "core"
Done 2018-10-09T20:35:41Z 2018-10-09T20:35:43Z Run hook connect-plug-system-observe of snap "lxd"

......................................................................
Make snap "core" (5548) available to the system

2018-10-09T20:35:38Z INFO Requested daemon restart.

ubuntu@cosmic-181009-1635:~$ snap change --abs-time 2
Status Spawn Ready Summary
Done 2018-10-09T20:35:36Z 2018-10-09T20:35:38Z Generate device key
Done 2018-10-09T20:35:36Z 2018-10-09T20:35:38Z Request device serial