On systems where XDG_DATA_DIRS is not set (e.g., debian), trying to open URLs from the Electron app using xdg-open fails.

[Ob1To]

On systems where XDG_DATA_DIRS is not set (e.g., debian), trying to
open URLs from the Electron app using xdg-open fails.

To reproduce:

unset XDG_DATA_DIRS
run the AppImage
Click a link in the AppImage app. See on
the console:
gvfs-open: https://something.com: error opening
location: No application is registered as handling this file

Hint:

The AppRun script does things like
export XDG_DATA_DIRS="./share/:${XDG_DATA_DIRS}"
export XDG_DATA_DIRS="${APPDIR}/usr/share:${XDG_DATA_DIRS}"
It should also put /usr/share/gnome:/usr/local/share/:/usr/share/ in
the list of paths if they are not there yet