Run `pub get` with --verbose to debug flaky timeouts on pkg tests

tools/testing/dart/test_suite.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Classes and methods for enumerating and preparing tests.
  *
  * This library includes:
  *
  * - Creating tests by listing all the Dart files in certain directories,
@@ skipping 1911 matching lines @@
 
         var directoryPath = absoluteDirectoryPath.relativeTo(TestUtils.dartDir);
         var testName = "$directoryPath";
         var displayName = '$suiteName/$testName';
 
         var checkoutDir =
             createPubPackageBuildsDirectory(absoluteDirectoryPath);
         var cacheDir = new Path(checkoutDir).append("pub-cache").toNativePath();
 
         // Build all commands
+        // In order to debug timeouts on the buildbots, We run `pub get` with
+        // "--verbose". See https://github.com/dart-lang/sdk/issues/28734.
         var commands = [
           CommandBuilder.instance.getCopyCommand(directory, checkoutDir),
           CommandBuilder.instance.getPubCommand(
-              "get", pubPath, checkoutDir, cacheDir)
+              "get", pubPath, checkoutDir, cacheDir, arguments: ['--verbose'])
         ];
 
         bool containsWebDirectory = dirExists(directoryPath.append('web'));
         bool containsBuildDartFile =
             fileExists(directoryPath.append('build.dart'));
         if (containsBuildDartFile) {
           var dartBinary = new File(dartVmBinaryFileName).absolute.path;
 
           commands.add(CommandBuilder.instance.getProcessCommand(
               "custom_build",
@@ skipping 474 matching lines @@
       }
       if (path.length > WINDOWS_SHORTEN_PATH_LIMIT) {
         ++shortNameCounter;
         var pathEnd = path.substring(path.length - WINDOWS_PATH_END_LENGTH);
         path = "short${shortNameCounter}_$pathEnd";
       }
     }
     return path;
   }
 }