anchor.diff:  import 'package:args/args.dart';
   import 'package:args/command_runner.dart';
   import 'package:http/http.dart' as http;
  +import 'package:path/path.dart' as p;
   
   import 'command/build.dart';
   import 'command/cache.dart';
  
positive.code:   Future runCommand(ArgResults options) async {
      log.withPrejudice = options['with-prejudice'];
  
      if (options['version']) {
        log.message('Pub ${sdk.version}');
        return;
  
negative.code: 
    void printUsage() {
      log.message(usage);
    }
  
    /// Print a warning if we're running from the Dart SDK repo and pub isn't
    /// up-to-date.
    ///
    /// This is otherwise hard to tell, and can produce confusing behavior issues.
    void _checkDepsSynced() {
      if (!runningFromDartRepo) return;
  
      var deps = readTextFile(p.join(dartRepoRoot, 'DEPS'));
      var pubRevRegExp = new RegExp(
          r'^ +"pub_rev": +"@([^"]+)"', multiLine: true);
      var match = pubRevRegExp.firstMatch(deps);
      if (match == null) return;
      var depsRev = match[1];
  
      var actualRev = git.runSync(["rev-parse", "HEAD"], workingDir: pubRoot)
          .single;
  
      if (depsRev == actualRev) return;
      log.warning(
          "${log.yellow('Warning:')} the revision of pub in DEPS is "
              "${log.bold(depsRev)},\n"
          "but ${log.bold(actualRev)} is checked out in "
              "${p.relative(pubRoot)}.\n\n");
    }
  
    /// Returns the appropriate exit code for [exception], falling back on 1 if no
  