anchor.diff:          await _benchmark("node", [p.join('build', 'npm', 'sass.js'), path]);
       buffer.writeln("* Dart Sass on Node.js: ${_formatTime(nodeTime)}");
   
  -    var rubyTime = await _benchmark(
  -        "ruby", ["-I", p.join(ruby, 'lib'), p.join(ruby, 'bin', 'sass'), path]);
  -    buffer.writeln("* Ruby Sass with a hot cache: ${_formatTime(rubyTime)}");
  -
       buffer.writeln();
       buffer.writeln('Based on these numbers, Dart Sass from a native executable '
           'is approximately:');
  
positive.code:     buffer.writeln('* ${_compare(nativeExecutableTime, sasscTime)} libsass');
      buffer.writeln(
          '* ${_compare(nativeExecutableTime, nodeTime)} Dart Sass on Node');
      buffer.writeln('* ${_compare(nativeExecutableTime, rubyTime)} Ruby Sass');
      buffer.writeln();
      log('');
    }
  
negative.code:           environment: {"SASS_LIBSASS_PATH": p.absolute(libsass)}));
    log("");
  
    var libsassRevision = await _revision(libsass);
    var sasscRevision = await _revision(sassc);
    var dartSassRevision = await _revision('.');
    var gPlusPlusVersion = await _version("g++");
    var nodeVersion = await _version("node");
  
    var perf = File("perf.md").readAsStringSync();
    perf = perf.replaceFirst(RegExp(r"This was tested against:\n\n[^]*?\n\n"), """
  