Don't hardcode linux as the build os in pub annotated

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 35 matching lines @@
   print "Running %s" % ' '.join(command)
   return bot.RunProcess(command)
 
 def PubSteps(build_info):
   sdk_bin = os.path.join(
       bot_utils.DART_DIR,
       utils.GetBuildSdkBin(BUILD_OS, build_info.mode, build_info.arch))
   pub_script_name = 'pub.bat' if build_info.system == 'windows' else 'pub'
   pub_bin = os.path.join(sdk_bin, pub_script_name)
 
-  pub_copy = os.path.join(utils.GetBuildRoot('linux'), 'pub_copy')
+  pub_copy = os.path.join(utils.GetBuildRoot(BUILD_OS), 'pub_copy')
   pub_location = os.path.join('third_party', 'pkg', 'pub')
 
   with bot.BuildStep('Make copy of pub for testing'):
     print 'Removing old copy %s' % pub_copy
     shutil.rmtree(pub_copy, ignore_errors=True)
     print 'Copying %s to %s' % (pub_location, pub_copy)
     shutil.copytree(pub_location, pub_copy)
 
   # TODO(nweiz): add logic for testing pub.
   with bot.BuildStep('Doing the magic ls'):
     with utils.ChangedWorkingDirectory(pub_copy):
       Run(['ls', '-l'])
 
   with bot.BuildStep('Running pub'):
     Run([pub_bin, '--version'])
 
 
 if __name__ == '__main__':
   bot.RunBot(PubConfig, PubSteps)