[Bug]: cannot verify snap "gimp", no matching signatures found when trying to install snap

[stillpointx]

What happened?

I'm getting this error when I try and install the gimp snap how can this be fixed?

error: cannot perform the following tasks:
Fetch and check assertions for snap "gimp" (412) (cannot verify snap "gimp", no matching signatures found)

rt@sys76:~$ sudo snap install gimp
error: cannot perform the following tasks:
- Fetch and check assertions for snap "gimp" (412) (cannot verify snap "gimp", no matching signatures found)
rt@sys76:~$ 

rt@sys76:~$ uname -a
Linux sys76 5.15.0-91-generic #101~20.04.1-Ubuntu SMP Thu Nov 16 14:22:28 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

What should have happened?

It should install

Output of snap info $snap_name

rt@sys76:~$ snap info gimp
name:      gimp
summary:   GNU Image Manipulation Program
publisher: Snapcrafters✪
store-url: https://snapcraft.io/gimp
contact:   https://github.com/snapcrafters/gimp/issues
license:   GPL-3.0+
description: |
  Whether you are a graphic designer, photographer, illustrator, or scientist, GIMP provides you
  with sophisticated tools to get your job done. You can further enhance your productivity with GIMP
  thanks to many customization options and 3rd party plugins.
  
  This snap is maintained by the Snapcrafters community, and is not necessarily endorsed or
  officially maintained by the upstream developers.
  
  Upstream Project: https://www.gimp.org/
  snapcraft.yaml Build Definition:
  https://github.com/snapcrafters/gimp/blob/master/snap/snapcraft.yaml
snap-id: KDHYbyuzZukmLhiogKiUksByRhXD2gYV
channels:
  latest/stable:     2.10.36 2023-12-06 (412) 539MB -
  latest/candidate:  ↑                              
  latest/beta:       ↑                              
  latest/edge:       2.10.36 2023-12-06 (412) 539MB -
  preview/stable:    –                              
  preview/candidate: –                              
  preview/beta:      –                              
  preview/edge:      2.99.10 2022-08-17 (397) 650MB -

Output of snap connections $snap_name

rt@sys76:~$ snap connections gimp
error: snap "gimp" not found
rt@sys76:~$

Output of snap version

rt@sys76:~$ snap version
snap    2.61.1
snapd   2.61.1
series  16
ubuntu  20.04
kernel  5.15.0-91-generic
rt@sys76:~$

Relevant log output

No response

Teminal output of app

No response

[popey]

I just tried installing the same snap, and the infrastructure and snap are fine, so it is likely a local issue.
Have you tried again? It's possible this was a transient issue.
Also, try snap download gimp and see if it downloads a .snap file and a .assert file.

[stillpointx]

Yes it still happens the only way to install gimp was to install another version using

sudo snap install gimp --channel=preview/edge
gimp 2.99.10 397 preview/edge snapcrafters✪ -

rt@sys76:~$ snap info gimp

  Upstream Project: https://www.gimp.org/
  snapcraft.yaml Build Definition:
  https://github.com/snapcrafters/gimp/blob/master/snap/snapcraft.yaml
snap-id: KDHYbyuzZukmLhiogKiUksByRhXD2gYV
channels:
  latest/stable:     2.10.36 2023-12-06 (412) 539MB -
  latest/candidate:  ↑                              
  latest/beta:       ↑                              
  latest/edge:       2.10.36 2023-12-06 (412) 539MB -
  preview/stable:    –                              
  preview/candidate: –                              
  preview/beta:      –                              
  preview/edge:      2.99.10 2022-08-17 (397) 650MB -
rt@sys76:~$ 

to install oldest from last line type below:

sudo snap install  gimp --channel=preview/edge

I purged gimp twice to make sure is wasn't there:

rt@sys76:/tmp/0$ sudo snap remove --purge gimp
snap "gimp" is not installed

rt@sys76:/tmp/0$ sudo snap install gimp
error: cannot perform the following tasks:
- Fetch and check assertions for snap "gimp" (412) (cannot verify snap "gimp", no matching signatures found)

It's like the "signature keys" aren't matching with the application.

Is there a way to reset the settings to see if that's causing it? What do I do with the .snap file and the .assert file?

[popey]

if snap download gimp worked then you can snap ack (followed by the assert filename) then snap install ./gimp*.snap