anchor.diff:      ioChoice syb time transformers
     ];
     buildTools = [ emacs ];
  +  doCheck = false;
     postInstall = ''
         cd $out/share/$pname-$version
         make
  
positive.code: 
  cabal.mkDerivation (self: {
    pname = "ghc-mod";
    version = "1.12.4";
    sha256 = "1f4pdwimzc2i7bb7ccpbl8pn18ygnqd65xw1z5cmhlswasbdab14";
    isLibrary = false;
    isExecutable = true;
    buildDepends = [
  
negative.code:       ensureDir "$out/share/emacs"
        mv $pname-$version emacs/site-lisp
      '';
    meta = {
      homepage = "http://www.mew.org/~kazu/proj/ghc-mod/";
      description = "Happy Haskell programming on Emacs/Vim";
  