Package: xmonad Followup-For: Bug #813154 Ok, so this is ghc platform-specific problem.
Installing i386 ghc binary allows the simplified as well as the full xmonad config to run. So either there is a bug in xmonad or one of the libraries that only manifests on ghc 7.10 on arm or something gets miscompiled. I don't have enough depth to debug ghc output so I will leave it at that. Thanks Michal