anchor.diff:  
         // Analyze package:ccc/c.dart and compute summary.
         {
  -        await _doDrive(cDart, uri: cUri, additionalArgs: [
  +        await _doDrive(cDart, fileUri: cUri, additionalArgs: [
             '--build-summary-input=$aSum,$bSum',
             '--build-summary-output=$cSum'
           ]);
  
positive.code: ''');
  
        await _doDrive(aDart,
            uri: aUri, additionalArgs: ['--build-summary-output=$aSum']);
        expect(exitCode, ErrorSeverity.ERROR.ordinal);
        var bytes = File(aSum).readAsBytesSync();
        var bundle = PackageBundle.fromBuffer(bytes);
  
negative.code:     args.add('--build-summary-output=${pkg.sum}');
      args.add('--summary-deps-output=${pkg.dep}');
  
      await _doDrive(pkg.path, fileUri: pkg.uri, additionalArgs: args);
      expect(exitCode, 0);
  
      return pkg;
  