Hey, because I have touble with ghci and packages with FFI, it was suggested to me to compile and use ghc HEAD. I am on xubuntu 13.04 64bit and try to do a perf build. It fails with: compiler/ghc.mk:478: warning: ignoring old commands for target `compiler/stage2/build/libHSghc-7.7.20131004-ghc7.7.20131004.so' "/home/ls/src/ghc/inplace/bin/haddock" --odir="libraries/ghc-prim/dist-install/doc/html/ghc-prim" --no-tmp-comp-dir --dump-interface=libraries/ghc-prim/dist-install/doc/html/ghc-prim/ghc-prim.haddock --html --hoogle --title="ghc-prim-0.3.1.0: GHC primitives" --prologue="libraries/ghc-prim/dist-install/haddock-prologue.txt" --optghc=-hisuf --optghc=dyn_hi --optghc=-osuf --optghc=dyn_o --optghc=-hcsuf --optghc=dyn_hc --optghc=-fPIC --optghc=-dynamic --optghc=-O --optghc=-H64m --optghc=-package-name --optghc=ghc-prim-0.3.1.0 --optghc=-hide-all-packages --optghc=-i --optghc=-ilibraries/ghc-prim/. --optghc=-ilibraries/ghc-prim/dist-install/build --optghc=-ilibraries/ghc-prim/dist-install/build/autogen --optghc=-Ilibraries/ghc-prim/dist-install/build --optghc=-Ilibraries/ghc-prim/dist-install/build/autogen --optghc=-Ilibraries/ghc-prim/. --optghc=-optP-include --optghc=-optPlibraries/ghc-prim/dist-install/build/autogen/cabal_macros.h --optghc=-package --optghc=rts-1.0 --optghc=-package-name --optghc=ghc-prim --optghc=-XHaskell98 --optghc=-XCPP --optghc=-XMagicHash --optghc=-XForeignFunctionInterface --optghc=-XUnliftedFFITypes --optghc=-XUnboxedTuples --optghc=-XEmptyDataDecls --optghc=-XNoImplicitPrelude --optghc=-O2 --optghc=-no-user-package-db --optghc=-rtsopts --optghc=-odir --optghc=libraries/ghc-prim/dist-install/build --optghc=-hidir --optghc=libraries/ghc-prim/dist-install/build --optghc=-stubdir --optghc=libraries/ghc-prim/dist-install/build libraries/ghc-prim/./GHC/Classes.hs libraries/ghc-prim/./GHC/CString.hs libraries/ghc-prim/./GHC/Debug.hs libraries/ghc-prim/./GHC/Magic.hs libraries/ghc-prim/dist-install/build/GHC/PrimopWrappers.hs libraries/ghc-prim/./GHC/IntWord64.hs libraries/ghc-prim/./GHC/Tuple.hs libraries/ghc-prim/./GHC/Types.hs libraries/ghc-prim/dist-install/build/autogen/GHC/Prim.hs +RTS -tlibraries/ghc-prim/dist-install/doc/html/ghc-prim/ghc-prim.haddock.t --machine-readable Haddock coverage: 100% ( 1 / 1) in 'GHC.IntWord64' 80% ( 8 / 10) in 'GHC.Types' 17% ( 1 / 6) in 'GHC.CString' 3% ( 2 / 63) in 'GHC.Tuple' 0% ( 0 / 3) in 'GHC.Debug' 0% ( 0 /366) in 'GHC.PrimopWrappers' 72% (813 /1132) in 'GHC.Prim' 100% ( 3 / 3) in 'GHC.Magic' 38% ( 6 / 16) in 'GHC.Classes' haddock: internal error: haddock: panic! (the 'impossible' happened) (GHC version 7.7.20131004 for x86_64-unknown-linux): Static flags have not been initialised! Please call GHC.parseStaticFlags early enough. Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug make[1]: *** [libraries/ghc-prim/dist-install/doc/html/ghc-prim/ghc-prim.haddock] Error 1 make: *** [all] Error 2 Suggestions? Thanks! Nathan