Snapd won't bind mount /usr/share/libdrm from Gnome snap

[Nathan Teodosio]

Chromium snap connects to gnome-42-2204 content snap[1]. It needs, among other things, /usr/share/libdrm/amdgpu.ids.

The gnome extension[2] is supposed to bind-mount the /usr/share/libdrm directory, but it remains empty:

--->
% snap connections chromium
content[gnome-42-2204] chromium:gnome-42-2204 gnome-42-2204:gnome-42-2204 -

% snap run --shell chromium
nteodosio@canonical:/home/nteodosio/canonical/the-new-stuff/security-center/packages/backend$ ls -la /usr/share/libdrm
total 0
drwxr-xr-x 2 root root 40 Feb 28 10:21 .
drwxr-xr-x 71 root root 1420 Feb 28 10:21 ..
<---

This is regardless of whether I add

--->
layout:
  /usr/share/libdrm:
    bind: $SNAP/gnome-platform/usr/share/libdrm
<---

to Chromium's snapcraft.yaml[3].

I think this might be a bug in Snapd as it's failing to mount the directory.

[1] https://raw.githubusercontent.com/ubuntu/gnome-sdk/gnome-42-2204-sdk/snapcraft.yaml
[2] https://github.com/canonical/snapcraft/blob/main/snapcraft/extensions/gnome.py#L173
[3] https://git.launchpad.net/~chromium-team/chromium-browser/+git/snap-from-source/tree/snapcraft.yaml#n105

[Nathan Teodosio (nteodosio)]

Adding to my confusion, Firefox' snapcraft.yaml[1] has the very same layout specified, and in 'snap run --shell firefox' /usr/share/libdrm/amdgpu.ids exists!

[1] https://git.launchpad.net/~mozilla-snaps/firefox-snap/+git/firefox-snap/tree/snapcraft.yaml#n113

[Nathan Teodosio (nteodosio)]

Amin pointed out to me that Firefox actually does have a work around for that: https://git.launchpad.net/~mozilla-snaps/firefox-snap/+git/firefox-snap/commit/?id=00059b6a9aea8e4ce5a239bd9e649f60736dd947.

[Nathan Teodosio (nteodosio)]

User confirmed in LP:2054887 that removing and installing makes the file appear, but not refreshing, so setting this to confirmed.