Thank you. That looks like something we could fix on the snapd side.
If you’d like to help verify, you could try editing the AppArmor profile that snapd generated for Firefox to see if it fixes things. This is a bit fiddly, so I would understand if you’d prefer not to.
These are the steps if you’re game:
/var/lib/snapd/apparmor/profiles/snap.firefox.firefox in a text editor. You’ll have to use sudo, as the file is only writable by root.
- In that file, search for “
- Insert a new line below that with the following contents (note that the trailing comma is important):
owner /run/user/[0-9]*/xauth_* r,
- Save the file. You can close the text editor now.
- Load the modified AppArmor profile into the kernel with the following command:
sudo apparmor_parser -r /var/lib/snapd/apparmor/profiles/snap.firefox.firefox
If everything has worked, you should be able to start Firefox now. Note that this fix is only temporary, and will likely be undone if any of the firefox or snapd snaps get updated. The real fix will be to get snapd to include this new rule in the profiles it generates.