[ZORG] Update Jenkins/build.py to force SVN upgrade of the working directory.

[sqlbyme]

Summary

When we upgrade Xcode on the bots connected to Green Dragon we need to automatically upgrade the SVN version of the current working directory repository. This patch also upgrades the function run_collect_output to work with a context manager. Using the context manager helps to ensure we always return to the directory we started working in.

[cmatthews]

Looks good, just change error message and node name stuff.

zorg/jenkins/build.py

75

I'd like this to be set to None, no need to have a string value here.

189

We know which machine things run on. No need to print that in the log message. On the other hand, printing the path to the workspace src dir that failed to upgrade would be super useful, since we may not know that from this error message.

[sqlbyme]

Adjusted code per comments from cmatthews.

[sqlbyme]

Chris Matthews asked me to make the above revisions and then go ahead and commit.

zorg/jenkins/build.py

 import math
 import re
 import xml.etree.ElementTree as ET
+from contextlib import contextmanager
 from urllib2 import urlopen, URLError, HTTPError
 
 SERVER = "labmaster2.local"

         self.nobootstrap = True
         self.device = None
         self._svn_url_cache = None
+        self.node_name = os.environ.get('NODE_NAME', 'Undefine_node_name')
 
         # Import all of the command line arguments into the config object
         self.__dict__.update(vars(args))

 conf = None  # type: Configuration
 
 
+def update_svn_checkouts():
+    """Upgrade the svn version.
+    
+    We always run this upgrade because this
+    helps us avoid bot breakage when we
+    upgrade Xcode.
+    """
+    try:
+        next_section("SVN upgrade")
+        out = run_collect_output(["/usr/bin/xcrun", "svn", "upgrade"],
+                                 working_dir=conf.srcdir())
+    except subprocess.CalledProcessError as e:
+        msg = """Process return code: {}\n
+              Error: on {} SVN upgrade failed.\n
+              The error was: {}.\n"""
+        msg = msg.format(e.returncode, conf.node_name, out)
+        print msg
+
+
 def cmake_builder(target):
     check_repo_state(conf.workspace)
+    update_svn_checkouts()
 
     env = []
     dyld_path = ""

 def clang_builder(target):
     """Build to set of commands to compile and test apple-clang"""
     check_repo_state(conf.workspace)
+    update_svn_checkouts()
+
     # get rid of old archives from prior builds
-
     run_ws(['sh', '-c', 'rm -rfv *gz'])
 
     if target == "all" or target == "build":

                                './Build',
                                './Root'])
             install_prefix = conf.installdir()
-            
             # Infer which CMake cache file to use. If ThinLTO we select a specific one.
             cmake_cachefile_thinlto = ''
             if conf.thinlto:

              }
 
 
-def run_collect_output(cmd):
-    """Run cmd, and return the output"""
+@contextmanager
+def cwd(path):
+    last_cwd = os.getcwd()
+    if path:
+        os.chdir(path)
+    try:
+        yield
+    finally:
+        os.chdir(last_cwd)
+
+
+def run_collect_output(cmd, working_dir=None, stderr=None):
+    """Run cmd and then return the output.
+    
+    If working_dir is supplied the cmd will run in
+    with a context manager in working_dir.
+    """
     if os.getenv("TESTING"):
         print 'TV: ' + ' '.join(cmd)
         return TEST_VALS[' '.join(cmd)]
 
-    return subprocess.check_output(cmd)
+    with cwd(working_dir):
+        return subprocess.check_output(cmd, stderr=stderr)
 
 
 def query_sys_tool(sdk_name, tool_name):