Give Invisible a definition for fail.
Give Invisible a definition for fail.

The default definition of fail calls error.  This is very bad, as we rely on a
non-bottom result.  We should consider moving to MonadZero, to be on the safe
side.

CaptainPatate/xmonad-contrib,ohlus/xmonad-contrib,ohlus/xmonad-contrib,0/xmonad-contrib,ohlus/xmonad-contrib,mathstuf/xmonad-contrib,mathstuf/xmonad-contrib,pjones/xmonad-test,CaptainPatate/xmonad-contrib,xmonad/xmonad-contrib,mathstuf/xmonad-contrib,xmonad/xmonad-contrib,0/xmonad-contrib,0/xmonad-contrib,f1u77y/xmonad-contrib,f1u77y/xmonad-contrib,CaptainPatate/xmonad-contrib