anchor.diff:      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('');
     }
  
positive.code:           environment: {"SASS_LIBSASS_PATH": p.absolute(libsass)}));
    log("");
  
    var ruby = await cloneOrPull('https://github.com/sass/ruby-sass');
    log("");
  
    var libsassRevision = await _revision(libsass);
    var sasscRevision = await _revision(sassc);
    var dartSassRevision = await _revision('.');
    var rubySassRevision = await _revision(ruby);
    var gPlusPlusVersion = await _version("g++");
    var nodeVersion = await _version("node");
    var rubyVersion = await _version("ruby");
  
    var perf = File("perf.md").readAsStringSync();
    perf = perf.replaceFirst(RegExp(r"This was tested against:\n\n[^]*?\n\n"), """
  
negative.code: Future<Duration> _benchmark(String executable, List<String> arguments) async {
    log("$executable ${arguments.join(' ')}");
  
    // Run the benchmark once without recording output to give implementations a
    // chance to warm up at the OS level.
    await _benchmarkOnce(executable, arguments);
  
    Duration lowest;
  