Trying to compile sources gives me: ghc: internal error: evacuate(static): strange closure type 34 (GHC version 6.10.4 for i386_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug This already occured to me some times before and a cleanup and recompile would work. This time i am stuck as i can't compile anymore. The ghc version i use is the 6.10.4 from the ghc home page binary distribution i think. uname -a gives : Linux localhost.localdomain 2.6.29.4-167.fc11.i586 #1 SMP Wed May 27 17:14:37 EDT 2009 i686 athlon i386 GNU/Linux The command line is: ghc -fwarn-incomplete-patterns -fno-warn-unused-binds -fno-warn-unused-matches -fno-warn-unused-imports -fno-warn-missing-signatures -fno-glasgow-exts -Werror -outputdir /tmp/mfk/build -package ghc -i/tmp/mfk/gensrc --make common/MFK/Common/SrcGen.hs common/MFK/Common/Conf.hs Any hints ?