build_scan: Raise ValueError on URL fetch error

scripts/slave/build_scan.py

 #!/usr/bin/env python
 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Scans a list of masters and saves information in a build_db."""
 
 from contextlib import closing
 import json
 import logging
@@ skipping 218 matching lines @@
 
   if not args:
     parser.error('you need to specify at least one master URL')
 
   args = [url.rstrip('/') for url in args]
 
   return options, args
 
 
 def get_updated_builds(masters, build_db, parallelism):
-  new_builds, master_jsons = find_new_builds_per_master(masters, build_db)
-  build_jsons = get_build_jsons(new_builds, parallelism)
-  propagate_build_json_to_db(build_db, build_jsons)
-  return master_jsons, build_jsons
+  try:
+    new_builds, master_jsons = find_new_builds_per_master(masters, build_db)
+    build_jsons = get_build_jsons(new_builds, parallelism)
+    propagate_build_json_to_db(build_db, build_jsons)
+    return master_jsons, build_jsons
+
+  # Catch this and raise a ValueError because this can be called from
+  # mulitprocessing, which can't pickle SSLContext objects, which apparently are
+  # properties of urllib2.URLError (it seems).
+  except (urllib2.URLError, IOError) as f:
+    msg = "URL Fetch timed out: %s" % f

[ghost stip (do not use), 2016/10/27 23:41:18]

probably want to make this something like "Error encountered during URL Fetch:",
it might not be a timeout?

[martiniss, 2016/10/27 23:44:04]

Done.

+    logging.error(msg)
+    raise ValueError(msg)
 
 
 def main():
   options, args = get_options()
 
   logging.basicConfig(level=logging.DEBUG if options.verbose else logging.INFO)
 
   masters = {}
   for m in set(args):
     masters[m] = BUILDER_WILDCARD
@@ skipping 11 matching lines @@
     print '%s:%s:%s' % (master_url, builder, buildnum)
 
   if not options.skip_build_db_update:
     build_scan_db.save_build_db(build_db, {}, options.build_db)
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())