Eventually, every Linux user opens an app and finds a generic placeholder icon staring back from their dock/panel. It looks like the dock is broken, but it almost never is - the cause is a single line in the app’s .desktop file, and it only takes a minute to fix. Here’s how to find it and fix it yourself, on any desktop.

As the maintainer of Plank Reloaded, the most common bug report I get is “this app has the wrong icon.” It’s almost never the dock - it’s a broken StartupWMClass in the app’s .desktop file. So I wrote up how to find the right value on X11, Wayland, and KDE, and why deleting the line often fixes it.

  • angel@sopuli.xyz
    5·
    5 个月前

    I use Firefox nightly and recently switched to Wayland (KDE). Ever since I switched, the taskbar often displays Firefox nightly with the regular Firefox icon, and the name Firefox instead of Firefox nightly. After reading your blog post I’m thinking that the culprit could be an incorrect StartupWMClass. But I don’t get why this issue never showed on X11 then.

    • zquestz@lemmy.worldOP
      3·
      5 个月前

      Yeah something isn’t being matched right. Might want to look at both .desktop files and compare them. Probably be pretty obvious when you look. =)

      • angel@sopuli.xyz
        0·
        5 个月前

        I just checked the .desktop file for firefox nightly. It contains only firefox-nightly as its StartupWMClass. So I went ahead and also checked the window class firefox nightly is running as and found the following: Screenshot showing the window properties of firefox nightly in the KDE system settings

        Does this mean that firefox nightly is using both, the firefox and the firefox-nightly window classes?

          • angel@sopuli.xyz
            2·
            5 个月前

            The desktop files are named firefox.desktop and firefox-nightly.desktop, both in /usr/share/applications.

            • zquestz@lemmy.worldOP
              0·
              5 个月前

              Yeah in your case the best fix is probably REMOVING StartupWMClass from those launchers if it is present. Then it will only match the app id on the .desktop file name.

              • angel@sopuli.xyz
                0·
                5 个月前

                Hmm, but I thought the StartupWMClasses in the desktop files are correct? I thought the issue is that firefox-nightly uses the firefox class in addition to the firefox-nightly class

  • RichardNixos@lemmy.ml
    1·
    5 个月前

    One thing I’ve noticed that’s funny is that sometimes when I use waypipe to launch a remote app locally it will have a random-ass icon, like a steam game or something

    • Crogdor@lemmy.world
      5·
      5 个月前

      This is literally what the article was created to explain. Just one more click, my guy, you’re almost there.