Experiment with running not running tests concurrently on pub on windows

tools/bots/pub.py

 #!/usr/bin/python
 
 # 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.
 
 """
 Pub buildbot steps.
 
 Runs tests for pub and the pub packages that are hosted in the main Dart repo.
@@ skipping 18 matching lines @@
     return None
 
   system = pub_pattern.group(1)
   locale = pub_pattern.group(3)
   mode = pub_pattern.group(5) or 'release'
   if system == 'win': system = 'windows'
 
   return bot.BuildInfo('none', 'vm', mode, system, checked=True,
                        builder_tag=locale)
 
-
 def PubSteps(build_info):
   with bot.BuildStep('Build package-root'):
     args = [sys.executable, './tools/build.py', '--mode=' + build_info.mode,
             'packages']
     print 'Building package-root: %s' % (' '.join(args))
     bot.RunProcess(args)
 
   common_args = ['--write-test-outcome-log']
   if build_info.builder_tag:
     common_args.append('--builder-tag=%s' % build_info.builder_tag)
-                
+
+
   # Pub tests currently have a lot of timeouts when run in debug mode.
   # See issue 18479
   if build_info.mode == 'release':
     bot.RunTest('pub', build_info,
                 common_args + ['pub', 'pkg', 'docs'])
   else:
     bot.RunTest('pub', build_info,
                 common_args + ['pkg', 'docs'])
-    
 
   if build_info.mode == 'release':
     pkgbuild_build_info = bot.BuildInfo('none', 'vm', build_info.mode,
                                         build_info.system, checked=False)
     bot.RunTest('pkgbuild_repo_pkgs', pkgbuild_build_info,
         common_args + ['--append_logs', '--use-repository-packages',
                        'pkgbuild'])
-    bot.RunTest('pkgbuild_public_pkgs', pkgbuild_build_info,
-        common_args + ['--append_logs', '--use-public-packages', 'pkgbuild'])
+
+    # We are seeing issues with pub get calls on the windows bots.
+    # Experiment with not running concurrent calls.
+    public_args = (common_args +
+                   ['--append_logs', '--use-public-packages', 'pkgbuild'])
+    if build_info.system == 'windows':
+      public_args.append('-j1')
+    bot.RunTest('pkgbuild_public_pkgs', pkgbuild_build_info, public_args)
 
 if __name__ == '__main__':
   bot.RunBot(PubConfig, PubSteps)