nixpkgs/pkgs/development/compilers/ghc/createGhcWrapper/default.nix

args: with args; with lib; with annotatedDerivations;

stdenv.mkDerivation {
  inherit suffix name ghc ;

  buildInputs = map delAnnotation (libraries ++ [ghcPkgUtil]);
  #tags = if (installSourceAndTags == true) then
  #        map sourceWithTagsDerivation ( uniqList { inputList = 
  #            ( filterAnnotated ( concatLists (map uniqAnnotatedDeps libraries ) ) ) ; } )
  #        else [];
  tags = map (x : sourceWithTagsDerivation (x.sourceWithTags)) 
          (uniqList { inputList=  filter annotatedWithSourceAndTagInfo libraries; } );

  phases="installPhase";

  installPhase="
    ensureDir \$out/bin
    if test -n \"\$ghcPackagedLibs\"; then
       g=:\$(echo \$ghc/lib/ghc-*/package.conf)
    fi

    for a in ghc ghci ghc-pkg; do
      app=$(ls -al $ghc/bin/$a | sed -n 's%.*-> \\(.*\\)%\\1%p');
cat > \"\$out/bin/\$a$suffix\" << EOF
#!`type -f sh | gawk '{ print $3; }'`
GHC_PACKAGE_PATH=\${GHC_PACKAGE_PATH}\${g} \$ghc/bin/$app \"\\\$@\"
EOF
      chmod +x \"\$out/bin/\$a$suffix\"
    done

    ensureDir \$out/{src,tags}
    for i in \$tags; do
      for path in src tags; do
        ln -s \$i/\$path/* \$out/\$path
      done
    done
";
}