[xmonad] How to diagnose programs not launching?

[Khudyakov Alexey]

On Friday 22 May 2009 23:31:53 Joseph Garvin wrote:
> I have a key set to runOrRaise "firefox3". Recently, it stopped
> working and I can't figure out why. Running firefox3 manually from the
> shell works fine, just not the shortcut. Is there a way to see what
> errors xmonad is receiving when it tries to run the command? I already
> tried looking at .xmonad/xmonad.errors, it just says:
>
> on the commandline:
>     Warning: -no-recomp is deprecated: Use -fforce-recomp instead
>
> Which I suspect is related to xmonad rather than my firefox call.
>
Another place to look is ~/.xession-errors.  It is file where xmonad's stdout 
and stderr are redirected. Outputs of processes created by xmonad are 
redirected to the same place. So if xmonad tries to launch something and it 
fails there is chance that it will write something meaningful to that file.