Comment 34 for bug 1932328

I set up a Fedora 33 VM to try and reproduce the issue there (Fedora 34 has GNOME 40, which the dash-to-dock extension isn't compatible with yet, and the problem is better observed with dash-to-dock configured to show one dot per open window). The default session is running on Wayland.

When running thunderbird 91.0 from the upstream tarball, I'm seeing that the icon displayed in the dock is the expected one when `MOZ_ENABLE_WAYLAND` is *not* set, however it's a generic cog icon when running with `MOZ_ENABLE_WAYLAND=1`.

Aside from that problem, I haven't managed to reproduce the issue described here with phantom windows yet, but I'll give it more tries, because it's not 100% reproducible on Ubuntu either.