[macOS/XQuartz] Launched application has wrong X11 `DISPLAY`, making application fail to launch

I can launch applications from the terminal just fine, and I can launch xfce4-appfinder itself just fine, but when I try to launch any application from xfce4-appfinder, it fails to launch:

(mousepad:19599): Gtk-WARNING **: 20:37:26.881: cannot open display: /private/tmp/com.apple.launchd.bQzI8WuvLg/org.xquartz:0.0

The proper display variable:

qwerty@macbook:~$ launchctl getenv DISPLAY
/private/tmp/com.apple.launchd.bQzI8WuvLg/org.xquartz:0
qwerty@macbook:~$ echo $DISPLAY
/private/tmp/com.apple.launchd.bQzI8WuvLg/org.xquartz:0

Oddly enough when I run echo $DISPLAY directly from xfce4-appfinder, the value is correct:

/private/tmp/com.apple.launchd.bQzI8WuvLg/org.xquartz:0

It seems when running a normal application, an extra .0 is getting added on to $DISPLAY somehow. Issue exists with both 4.18.1 and 4.19.2. I'm happy to help debug, just need a pointer on what direction to look in.

I am able to (temporarily) work around the issue by running this:

ln -s /private/tmp/com.apple.launchd.bQzI8WuvLg/org.xquartz:0 /private/tmp/com.apple.launchd.bQzI8WuvLg/org.xquartz:0.0

That confirms the extra .0 is the issue, I'm just not sure where it is being added.

Thanks for your interest in playing with appfinder under macOS. I happen to have an Mac device around, but unfortunately I unable spend too much time trying to figure out how to compile appfinder in this OS. How did you install it, via Macports? Are you able to compile and run from source? Instructions would be appreciated.

If you're interested in digging a bit deeper, you may want to look at the function xfce_appfinder_model_execute and perhaps xfce_spawn from libxfce4ui. By the way, does it make any difference when launching apps in expanded and collapsed modes?

added 3. Need Info label

Recently I started to try to use some Xfce apps under macOS, as a result I have created my own brew tap: https://github.com/andreldm/homebrew-xfce

I cannot reproduce this bug when appfinder is installed from that tap, can you please try it?