Comment #14 on issue 576 by allber...@gmail.com: On FreeBSD Xmonad loses first hotkey sometimes https://code.google.com/p/xmonad/issues/detail?id=576 spawn is handing it upstream to IO via liftIO, as indicated by the MonadIO constraint; this should be negligible overhead (nanoseconds if it's not optimized away entirely which it should be). The periodic itimer and SIGALRM handler are used by GHC's runtime for thread scheduling, profiler ticks, and IIRC determining when to do a full instead of partial garbage collection, among other things. Also, which function type descriptions are missing? I am looking at http://xmonad.org/xmonad-docs/xmonad/XMonad-Core.html#v:spawn -- You received this message because this project is configured to send all issue notifications to this address. You may adjust your notification preferences at: https://code.google.com/hosting/settings