Fixing application issues (hidden or not launching)

[friday]

Ulauncher uses GTK's APIs to handle applications. If your applications doesn't show up in Ulauncher, this is not an issue with Ulauncher. It is either because the desktop entry file is in the wrong path, doesn't comply with the freedesktop specifications, or that is has an invalid path to the executable. This could be caused by this KDE bug for example.

By default (unless you have specified otherwise in your XDG_DATA_DIRS variable) the paths the application indexer is searching are /usr/share/applications/ and ~/.local/share/applications. The former is where system packages tend to install desktop entries. These are rarely invalid/broken, but the local in your home dir overrides the ones in the system path. So if you have a file with the same name in both these directories the second one will be used. If that one is invalid, it might not show up even if the other one is valid.

To find the issue, first find the desktop entry file(s) for the app(s) that are not showing. If you can't find it in the paths previously mentioned, this is likely the cause of the issue. It's possible to configure your system differently so the locations would be elsewhere, but we assume any users doing so would be able to "translate" these instructions for their paths.

If you do find the file, first check that the command to launch the app as specified in the desktop entry's Exec line corresponds to an actual existing file and that it has the execute permission.

If this doesn't fix the issue, make sure you have desktop-file-utils. Then you can validate the file(s).

This command should show all validation issues for all your local desktop entries:

desktop-file-validate  ~/.local/share/applications/**/*.desktop

Fix these issues manually to fix your applications.