Flush stdout before shelling out.

testing/test_env.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """Sets environment variables needed to run a chromium unit test."""
 
 import os
 import stat
 import subprocess
@@ skipping 193 matching lines @@
 
   # Ensure paths are correctly separated on windows.
   cmd[0] = cmd[0].replace('/', os.path.sep)
   cmd = fix_python_path(cmd)
 
   print('Additional test environment:\n%s\n'
         'Command: %s\n' % (
         '\n'.join('    %s=%s' %
             (k, v) for k, v in sorted(extra_env.iteritems())),
         ' '.join(cmd)))
+  sys.stdout.flush()
   env.update(extra_env or {})
   try:
     # See above comment regarding offline symbolization.
     if use_symbolization_script:
       # Need to pipe to the symbolizer script.
       p1 = subprocess.Popen(cmd, env=env, stdout=subprocess.PIPE,
                             stderr=sys.stdout)
       p2 = subprocess.Popen(
           get_sanitizer_symbolize_command(executable_path=cmd[0]),
           env=env, stdin=p1.stdout)
       p1.stdout.close()  # Allow p1 to receive a SIGPIPE if p2 exits.
       p1.wait()
       p2.wait()
       # Also feed the out-of-band JSON output to the symbolizer script.
       symbolize_snippets_in_json(cmd, env)
       return p1.returncode
     else:
       return subprocess.call(cmd, env=env)
   except OSError:
     print >> sys.stderr, 'Failed to start %s' % cmd
     raise
 
 
 def main():
   return run_executable(sys.argv[1:], os.environ.copy())
 
 
 if __name__ == '__main__':
   sys.exit(main())