Error message trying to refresh or uninstalling a snap ( gimp )

[Coeur Noir]

Hi,

as suggested here : https://forum.snapcraft.io/t/gimp-ubuntu-16-04-suddenly-stops-working/18393/8?u=coeur-noir

I had some error messages following auto-refresh for gimp or trying to uninstall this snap, on Ubuntu 16.04 ( this did not happen on 20.04 ).

When trying to launch it :

palace4@proliant:~$ gimp
ln: failed to create symbolic link '/home/palace4/snap/gimp/273/.config/gtk-2.0/gtkfilechooser.ini': File exists
/snap/gimp/273/usr/bin/gimp: error while loading shared libraries: libgdk_pixbuf-2.0.so.0: cannot open shared object file: No such file or directory
palace4@proliant:~$

And if trying to remove it :

palace4@proliant:~$ sudo snap remove gimp
error: cannot perform the following tasks:
- Disconnect gimp:removable-media from snapd:removable-media (cannot update mount namespace of snap "gimp": cannot update preserved namespace of snap "gimp":
-----
update.go:85: cannot change mount namespace according to change unmount (/var/lib/snapd/hostfs/var/cache/fontconfig /var/cache/fontconfig none bind,ro 0 0): invalid argument
cannot update snap namespace: no such file or directory
-----)
palace4@proliant:~$

It's related to a newer version of gimp :

palace4@proliant:~$ snap changes
ID Status Spawn Ready Summary
7 Error today at 00:59 CEST today at 00:59 CEST Auto-refresh snap "gimp"
8 Error today at 06:19 CEST today at 06:19 CEST Auto-refresh snap "gimp"
9 Error today at 16:04 CEST today at 16:04 CEST Auto-refresh snap "gimp"
10 Error today at 19:58 CEST today at 19:58 CEST Remove "gimp" snap
11 Error today at 20:00 CEST today at 20:00 CEST Remove "gimp" snap
12 Error today at 20:59 CEST today at 20:59 CEST Auto-refresh snaps "gtk2-common-themes", "gimp"

palace4@proliant:~$

If trying manually :

palace4@proliant:~$ sudo snap refresh
[sudo] Mot de passe de palace4 :
error: cannot perform the following tasks:
- Setup snap "gimp" (281) security profiles (cannot update mount namespace of snap "gimp": cannot update preserved namespace of snap "gimp":
-----
update.go:85: cannot change mount namespace according to change unmount (/var/lib/snapd/hostfs/var/cache/fontconfig /var/cache/fontconfig none bind,ro 0 0): invalid argument
cannot update snap namespace: no such file or directory
-----)
palace4@proliant:~$

Finally this has solved the issue :

palace4@proliant:~$ sudo /usr/lib/snapd/snap-discard-ns gimp
[sudo] Mot de passe de palace4 :
palace4@proliant:~$ sudo snap refresh
gimp 2.10.20 from Snapcrafters refreshed
palace4@proliant:~$ gimp
ln: failed to create symbolic link '/home/palace4/snap/gimp/281/.config/gtk-2.0/gtkfilechooser.ini': File exists
Gtk-Message: 22:09:23.760: Failed to load module "overlay-scrollbar"
/snap/gimp/281/usr/bin/gimp: Gimp-Widgets-AVERTISSEMENT: parse_iso_codes: error parsing '/build/gimp/parts/gimp/install/usr/share/xml/iso-codes/iso_639.xml': No such file or directory

Gtk-Message: 22:09:29.759: Failed to load module "overlay-scrollbar"
Gtk-Message: 22:09:37.780: Failed to load module "overlay-scrollbar"
/snap/gimp/281/usr/bin/gimp: LibGimpBase-AVERTISSEMENT: gimp: gimp_wire_read(): error
Gtk-Message: 22:09:38.911: Failed to load module "overlay-scrollbar"
Gtk-Message: 22:09:39.332: Failed to load module "overlay-scrollbar"
gimp_check_updates_callback: loading of https://gimp.org/gimp_versions.json failed: Operation not supported

I hope it makes sense for you ;-)

[Maciej Borzecki (maciek-borzecki)]

Zyga you're probably the right person to look at the bug.

[Paweł Stołowski (stolowski)]

Similar problem reported a day later, also for gimp: https://bugs.launchpad.net/ubuntu/+source/snapd/+bug/1884930

[Zygmunt Krynicki (zyga)]

I was unable to reproduce this yet but looking at the errors I have an idea what can be going on. I will try to write a test case to artificially force a condition where this would happen and adjust the code to handle it.

[Zygmunt Krynicki (zyga)]

I've proposed a pull request that addresses the symptom you've experienced:

https://github.com/snapcore/snapd/pull/8961