Use subprocess42 in recipe_engine to avoid threading madness.

recipe_engine/unittests/run_test.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.
 
 import json
 import os
 import re
 import subprocess
 import sys
 import unittest
+import time
 
 BASE_DIR = os.path.dirname(os.path.dirname(os.path.dirname(
                            os.path.abspath(__file__))))
 THIRD_PARTY = os.path.join(BASE_DIR, 'recipe_engine', 'third_party')
 sys.path.insert(0, os.path.join(THIRD_PARTY, 'mock-1.0.1'))
 sys.path.insert(0, BASE_DIR)
 
 import recipe_engine.run
 import recipe_engine.step_runner
 from recipe_engine import recipe_test_api
@@ skipping 114 matching lines @@
         return None
 
     with self.assertRaises(AssertionError):
       engine.run(FakeScript(), api)
 
   def test_subannotations(self):
     proc = subprocess.Popen(
         self._run_cmd('engine_tests/subannotations'),
         stdout=subprocess.PIPE,
         stderr=subprocess.PIPE)
-    stdout, stderr = proc.communicate()
+    stdout, _ = proc.communicate()
     self.assertRegexpMatches(stdout, r'(?m)^!@@@BUILD_STEP@steppy@@@$')
     self.assertRegexpMatches(stdout, r'(?m)^@@@BUILD_STEP@pippy@@@$')
     # Before 'Subannotate me' we expect an extra STEP_CURSOR to reset the
     # state.
     self.assertRegexpMatches(stdout,
         r'(?m)^@@@STEP_CURSOR@Subannotate me@@@\n@@@STEP_CLOSED@@@$')
 
+  def test_bad_subprocess(self):
+    now = time.time()
+    self._test_recipe('engine_tests/bad_subprocess')
+    after = time.time()
+
+    # Test has an internal 10s timeout for the bad daemon step, but the daemon's
+    # parent process quits immediately. If this takes longer than 5 seconds to
+    # run, we consider it failed.
+    self.assertLess(after - now, 5)
+
 
 if __name__ == '__main__':
   unittest.TestCase.maxDiff = None
   unittest.main()