anchor.diff:  
       echo -n "${buildMK}" > mk/build.mk
       sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
  +  '' + stdenv.lib.optionalString (stdenv.isLinux) ''
  +    export LOCALE_ARCHIVE="${glibcLocales}/lib/locale/locale-archive"
     '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
       export NIX_LDFLAGS+=" -rpath $out/lib/ghc-${version}"
     '' + stdenv.lib.optionalString stdenv.isDarwin ''
  
positive.code: , bash
  
  , libiconv ? null, ncurses
  
  , # GHC can be built with system libffi or a bundled one.
    libffi ? null
  
negative.code: 
    postPatch = "patchShebangs .";
  
    # GHC needs the locale configured during the Haddock phase.
    LANG = "en_US.UTF-8";
  
    # GHC is a bit confused on its cross terminology.
    preConfigure = ''
      for env in $(env | grep '^TARGET_' | sed -E 's|\+?=.*||'); do
  