Comment #5 on issue 336 by pepeibo...@gmail.com: xmonad won't start: Irrefutable pattern failed for pattern (Data.Maybe.Just nbc_) http://code.google.com/p/xmonad/issues/detail?id=336 I can reproduce this problem on a clean Snow Leopard installation. Installed GHC 6.10.4, then the Haskell platform and then "cabal install xmonad". This is the output of "cabal install xmonad" pepe:~/.cabal/packages/hackage.haskell.org/xmonad/0.9/xmonad-0.9$ cabal install Resolving dependencies... Configuring xmonad-0.9... Preprocessing library xmonad-0.9... ld: warning: in /Library/Frameworks/GHC.framework/Versions/610/usr/lib/ghc-6.10.4/libgmp.a, file is not of required architecture Preprocessing executables for xmonad-0.9... ld: warning: in /Library/Frameworks/GHC.framework/Versions/610/usr/lib/ghc-6.10.4/libgmp.a, file is not of required architecture Building xmonad-0.9... [1 of 8] Compiling XMonad.StackSet ( XMonad/StackSet.hs, dist/build/XMonad/StackSet.o ) [2 of 8] Compiling XMonad.Core ( XMonad/Core.hs, dist/build/XMonad/Core.o ) [3 of 8] Compiling XMonad.Layout ( XMonad/Layout.hs, dist/build/XMonad/Layout.o ) [4 of 8] Compiling XMonad.Operations ( XMonad/Operations.hs, dist/build/XMonad/Operations.o ) [5 of 8] Compiling XMonad.ManageHook ( XMonad/ManageHook.hs, dist/build/XMonad/ManageHook.o ) [6 of 8] Compiling XMonad.Config ( XMonad/Config.hs, dist/build/XMonad/Config.o ) [7 of 8] Compiling XMonad.Main ( dist/build/XMonad/Main.hs, dist/build/XMonad/Main.o ) [8 of 8] Compiling XMonad ( XMonad.hs, dist/build/XMonad.o ) ar: creating archive dist/build/libHSxmonad-0.9.a [ 1 of 10] Compiling Paths_xmonad ( dist/build/autogen/Paths_xmonad.hs, dist/build/xmonad/xmonad- tmp/Paths_xmonad.o ) [ 2 of 10] Compiling XMonad.StackSet ( XMonad/StackSet.hs, dist/build/xmonad/xmonad- tmp/XMonad/StackSet.o ) [ 3 of 10] Compiling XMonad.Core ( XMonad/Core.hs, dist/build/xmonad/xmonad-tmp/XMonad/Core.o ) [ 4 of 10] Compiling XMonad.Layout ( XMonad/Layout.hs, dist/build/xmonad/xmonad- tmp/XMonad/Layout.o ) [ 5 of 10] Compiling XMonad.Operations ( XMonad/Operations.hs, dist/build/xmonad/xmonad- tmp/XMonad/Operations.o ) [ 6 of 10] Compiling XMonad.ManageHook ( XMonad/ManageHook.hs, dist/build/xmonad/xmonad- tmp/XMonad/ManageHook.o ) [ 7 of 10] Compiling XMonad.Config ( XMonad/Config.hs, dist/build/xmonad/xmonad- tmp/XMonad/Config.o ) [ 8 of 10] Compiling XMonad.Main ( dist/build/xmonad/xmonad-tmp/XMonad/Main.hs, dist/build/xmonad/xmonad-tmp/XMonad/Main.o ) [ 9 of 10] Compiling XMonad ( XMonad.hs, dist/build/xmonad/xmonad-tmp/XMonad.o ) [10 of 10] Compiling Main ( Main.hs, dist/build/xmonad/xmonad-tmp/Main.o ) Linking dist/build/xmonad/xmonad ... Preprocessing library xmonad-0.9... Preprocessing executables for xmonad-0.9... Running Haddock for xmonad-0.9... Warning: The documentation for the following packages are not installed. No links will be generated to these packages: rts-1.0 Warning: XMonad.Core: could not find link destinations for: XMonad.Layout.NextNoWrap Warning: XMonad.Config: could not find link destinations for: XMonad.Config.defaultConfig Documentation created: dist/doc/html/xmonad/index.html Installing library in /Users/pepe/.cabal/lib/xmonad-0.9/ghc-6.10.4 Installing executable(s) in /Users/pepe/.cabal/bin Registering xmonad-0.9... Reading package info from "dist/installed-pkg-config" ... done. Writing new package config file... done. Then this is the output of "xmonad" pepe:~$ xmonad /Users/pepe/.xmonad/xmonad-i386-darwin: executeFile: does not exist (No such file or directory) xmonad: XMonad/Main.hsc:(82,14)-(84,41): Irrefutable pattern failed for pattern (Data.Maybe.Just nbc_) And then this is the output of "xmonad --recompile" pepe:~$ xmonad --recompile xmonad: /Users/pepe/.xmonad/xmonad.errors: openFile: does not exist (No such file or directory) -- You received this message because you are listed in the owner or CC fields of this issue, or because you starred this issue. You may adjust your issue notification preferences at: http://code.google.com/hosting/settings