anchor.diff:            precompiledPath,
           ]..addAll(extraTestArgs),
           mode: ProcessStartMode.inheritStdio);
  +    _ensureProcessExit(testProcess);
       return testProcess.exitCode;
     }
   }
  
positive.code:   }
  }
  
  class _BuildTestDependencyError extends StateError {
    _BuildTestDependencyError() : super('''
  Missing dev dependency on package:build_test, which is required to run tests.
  
negative.code: import 'dart:io';
  
  import 'package:args/command_runner.dart';
  import 'package:async/async.dart';
  import 'package:build_runner_core/build_runner_core.dart';
  import 'package:io/io.dart';
  import 'package:path/path.dart' as p;
  