Since using bash instead of fish fixes the issue, I think the problem lies in the snapd+fish integration. Possible workarounds:
1. Revert to bash via chsh as stated above
2. Upgrade fish to 3.2.0 which contains the fish_add_path
3. Wait for newer snapd (which reportedly contains a compatibility fix to continue working with fish 3.1)
Since using bash instead of fish fixes the issue, I think the problem lies in the snapd+fish integration. Possible workarounds:
1. Revert to bash via chsh as stated above
2. Upgrade fish to 3.2.0 which contains the fish_add_path
3. Wait for newer snapd (which reportedly contains a compatibility fix to continue working with fish 3.1)
Also see https:/ /bugs.launchpad .net/ubuntu/ +source/ snapd/+ bug/1957948