Snap app crashes if upgraded in the background

[bast1aan]

-- Copy of bug report on signalapp/Signal-Desktop#3793 --

• I have searched open and closed issues for duplicates

---

Bug Description

The Signal Desktop Snap app in Ubuntu 18.04 crashes after a running for a while with following error message:

Unhandled Error

Error: EACCES: permission denied, rename '/home/bwelmers/snap/signal-desktop/219/.config/Signal/logs/log.log.1' -> '/home/bwelmers/snap/signal-desktop/219/.config/Signal/logs/log.log.2'

When looking in the list of Signal snap versions:

/dev/loop7                              98M   98M     0 100% /snap/signal-desktop/219
/dev/loop10                             98M   98M     0 100% /snap/signal-desktop/235

it looks like the snap is upgraded in the background and somehow the running instance of Signal does not handle this correctly and keeps trying to use the older config directory.

Steps to Reproduce

Unfortunately not easy, but something like this

1. install signal-desktop snap app and launch it, login to it, use it etc
2. let it run until a new version is installed by snapd
3. wait until the log needs to be rotated. Looks like that is done on daily basis.

Actual Result:

Crash

Expected Result:

Should not crash.

Screenshots

Platform Info

Signal Version:

Name            Version  Rev  Tracking  Publisher     Notes
signal-desktop  1.29.0   235  stable    snapcrafters  -

Operating System:

Ubuntu 18.04

Linked Device Version:

Android: Signal 4.49.18

Link to Debug Log

https://debuglogs.org/604b3bb6f1cc01244899b902643643d3503981433d3377526d5f671b96b89c12

[popey]

We have an experimental feature, designed to mitigate this issue. It's blogged about at https://ubuntu.com/blog/experimental-feature-snap-refresh-awareness-and-update-inhibition
This issue is indeed a snap-related one, and we're working to get that feature landed by default as soon as we can. For now, this is the workaround.

snap set core experimental.refresh-app-awareness=true

This will prevent the app updating while it's running.

[johnmee]

Forgive my naivety, but could this be fixed with a "snap layout"?

https://snapcraft.io/docs/snap-layouts

[lucyllewy]

no, snap layouts are completely orthogonal to this issue

[merlijn-sebrechts]

Note: duplicate of #8