Add a little print debugging to determine what's hanging

scripts/run_cmd.py

 #!/usr/bin/env python
 # Copyright (c) 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.
 
 
 """Run a command and report its results in machine-readable format."""
 
 
 import collections
@@ skipping 289 matching lines @@
   procs = []
 
   for hostname in slave_hosts_cfg.SLAVE_HOSTS.iterkeys():
     if not slave_hosts_cfg.SLAVE_HOSTS[hostname].login_cmd:
       results.update(
           {hostname: CommandResults.make(stderr='No procedure for login.')})
     else:
       procs.append((hostname, _launch_on_remote_host(hostname, cmd)))
 
   for slavename, proc in procs:
+    print 'Awaiting results from %s' % slavename
     results.update(_get_remote_host_results(slavename, proc))
 
   return results
 
 
 def parse_args(positional_args=None):
   """Common argument parser for scripts using this module.
 
   Args:
       positional_args: optional list of strings; extra positional arguments to
@@ skipping 28 matching lines @@
     setattr(options, cmd, args)
   except IndexError:
     parser.print_usage()
     sys.exit(1)
   return options
 
 
 if '__main__' == __name__:
   parsed_args = parse_args()
   run(parsed_args.cmd).print_results(pretty=parsed_args.pretty)