anchor.diff:          installFlags = stdenv.lib.optionalString docSupport "install-doc";
           # Bundler tries to create this directory
           postInstall = ''
  -          # Update rubygems
  -          pushd rubygems
  -          chmod +w bundler/bundler.gemspec
  -          ${buildRuby} setup.rb --destdir $GEM_HOME
  -          popd
  -
             # Remove unnecessary groff reference from runtime closure, since it's big
             sed -i '/NROFF/d' $out/lib/ruby/*/*/rbconfig.rb
   
  
positive.code:           EOF
  
            rbConfig=$(find $out/lib/ruby -name rbconfig.rb)
          '' + opString docSupport ''
            # Prevent the docs from being included in the closure
            sed -i "s|\$(DESTDIR)$devdoc|\$(datarootdir)/\$(RI_BASE_NAME)|" $rbConfig
  
negative.code:     baseruby = self.override {
        useRailsExpress = false;
        docSupport = false;
        rubygemsSupport = false;
      };
      self = lib.makeOverridable (
        { stdenv, buildPackages, lib
        , fetchurl, fetchFromSavannah, fetchFromGitHub
        , useRailsExpress ? true
        , rubygemsSupport ? true
        , zlib, zlibSupport ? true
        , openssl, opensslSupport ? true
        , gdbm, gdbmSupport ? true
  