Fish has incorrect XDG_DATA_DIRS variable

[Jonathan Coatess]

In https://bugs.launchpad.net/snapd/+bug/1951145 and https://github.com/snapcore/snapd/pull/11071, some Fish configuration was added to ensure XDG_DATA_DIRS contains Snap's desktop directory.

However, this does not appear to work on my system, instead XDG_DATA_DIRS ends up with having spaces in it, meaning the applications are not found:

~ ᐅ fish --version
fish, version 3.3.1
~ ᐅ echo $XDG_DATA_DIRS
/usr/local/share/:/usr/share/:/var/lib/snapd/desktop /var/lib/snapd/desktop /var/lib/snapd/desktop
~ ᐅ bash -c 'echo "$XDG_DATA_DIRS"'
/usr/local/share/:/usr/share/:/var/lib/snapd/desktop /var/lib/snapd/desktop /var/lib/snapd/desktop

It appears the original PR was appending the variable to the XDG_DATA_DIRS array. However, in recent versions of Fish, the variable is _not_ an array (see https://github.com/fish-shell/fish-shell/issues/436 I think), and so this is treated as basic string concatenation.

[Maciej Borzecki (maciek-borzecki)]

I believe this was addressed in https://github.com/snapcore/snapd/pull/11221 which landed just recently. You can install the snapd snap from edge and then copy /snap/snapd/current/usr/share/fish/vendor_conf.d/snapd.fish to /usr/share/fish/vendor_conf.d/ and verify if that works for you?

[Jonathan Coatess (squiddev)]

Can confirm this fixes it, thank you very much!

Sorry - searched launchpad, but didn't think to search PRs/check the current state of the tree. Woops!

[Andy Goossens (andygoossens)]

I got hit by the same issue on Ubuntu 21.10 with snapd version 2.54.2+21.10ubuntu1.

Patching the file as described in #1 fixes it for me.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Andy Goossens (andygoossens)]

Hm, I suspect that the update broke my desktop environment (Plasma Desktop).

Earlier today I received the 2.54.3+21.10.1ubuntu0.1 update. And when I rebooted, my Plasma Desktop was broken. Applications that were still open worked (Firefox, Konsole), but task panel was absent, icons missing, ...

Note that I am using Fish shell as my default shell. When I use Bash however, the Plasma Desktop is working fine.

When logging in on TTY with Bash as default shell:
XDG_DATA_DIRS == /usr/share/local:/usr/share:/usr/lib/snapd/desktop
When I log in with Fish:
XDG_DATA_DIRS == /usr/lib/snapd/desktop

That would explain why my desktop got broken.

To reproduce:
* create a new user account "test"
* start Plasma session with user "test", everything looks fine
* execute: chsh -s /usr/bin/fish
* log out
* log in again, things are broken

Workaround: Use Bash as default shell. Configure your terminal emulator to use Fish.

EDIT:
For good measure: After removing+purging snapd, the desktop starts up properly.
However, executing "echo $XDG_DATA_DIRS" with Fish returns nothing in that case. Not sure what to think about that.

[Andy Goossens (andygoossens)]

I have created a separate bug report as I am not the only one hitting this issue:
https://bugs.launchpad.net/snapd/+bug/1961791