anchor.diff:    buildInputs = [ hepmc imagemagick python2 latex makeWrapper ];
     propagatedBuildInputs = [ fastjet ghostscript gsl yoda ];
   
  +  preConfigure = ''
  +    substituteInPlace bin/rivet-buildplugin.in \
  +      --replace '"which"' '"${which}/bin/which"' \
  +      --replace 'mycxx=' 'mycxx=${stdenv.cc}/bin/${if stdenv.cc.isClang or false then "clang++" else "g++"}  #' \
  +      --replace 'mycxxflags="' "mycxxflags=\"-std=c++11 $NIX_CFLAGS_COMPILE $NIX_CXXSTDLIB_COMPILE $NIX_CFLAGS_LINK "
  +  '';
  +
     preInstall = ''
       substituteInPlace bin/make-plots \
         --replace '"which"' '"${which}/bin/which"' \
  
positive.code: 
  stdenv.mkDerivation rec {
    name = "rivet-${version}";
    version = "2.5.4";
  
    src = fetchurl {
      url = "http://www.hepforge.org/archive/rivet/Rivet-${version}.tar.bz2";
      sha256 = "1qi7am60f2l4krd3sbj95mbzfk82lir0wy8z27yr9ncq6qcm48kp";
    };
  
    postPatch = "patchShebangs ./src/Analyses/cat_with_lines";
  
    patches = [
      ./darwin.patch # configure relies on impure sw_vers to -Dunix
  
negative.code:       --replace '"convert"' '"${imagemagick.out}/bin/convert"'
      substituteInPlace bin/rivet \
        --replace '"less"' '"${less}/bin/less"'
      substituteInPlace bin/rivet-mkhtml \
        --replace '"make-plots"' \"$out/bin/make-plots\" \
        --replace '"rivet-cmphistos"' \"$out/bin/rivet-cmphistos\"
  