anchor.diff:              output: isNot(contains('PUB_ALLOW_PRERELEASE_SDK')));
         });
   
  -      test("no min pre-release constraint that matches the current SDK",
  -          () async {
  +      test("lower bound is pre-release and matches SDK", () async {
           await d.dir(appPath, [
             await d.pubspec({
               'name': 'myapp',
  
positive.code:       });
      });
  
      group("allows", () {
        test("an exclusive max that matches the current SDK", () async {
          await d.dir(appPath, [
            await d.pubspec({
              'name': 'myapp',
  
negative.code:             output: isNot(contains('PUB_ALLOW_PRERELEASE_SDK')));
        });
  
        test("patch SDK versions differ", () async {
          await d.dir(appPath, [
            await d.pubspec({
              'name': 'myapp',
  