anchor.diff:          summary = await analyzer.inspectPackage(package,
               version: version, options: options);
         } else if (source == 'path') {
  -        final path = firstArg('No path was provided.');
  +        final path = firstArg() ?? '.';
           final absolutePath = await Directory(path).resolveSymbolicLinks();
           if (showWarning) {
             log.Logger.root
  
positive.code:       help:
            'The source where the package is located (hosted on $defaultHostedUrl, or local directory path).',
        allowed: ['hosted', 'path'],
        defaultsTo: 'hosted')
    ..addOption('hosted-url',
        help: 'The server that hosts <package>.', defaultsTo: defaultHostedUrl)
    ..addOption('line-length',
  
negative.code:   final source = result['source'];
    final verbosity = Verbosity.values
        .firstWhere((v) => v.toString().split('.').last == result['verbosity']);
    String firstArg() {
      return result.rest.isEmpty ? null : result.rest.first;
    }
  
    log.Logger.root.level = log.Level.ALL;
  