Update EbuildIpcDaemon to open files as non-blocking.

pym/_emerge/EbuildIpcDaemon.py

 # Copyright 2010 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
 import errno
 import pickle
 from portage import os
 from _emerge.FifoIpcDaemon import FifoIpcDaemon
 from _emerge.PollConstants import PollConstants
 
 class EbuildIpcDaemon(FifoIpcDaemon):
@@ skipping 66 matching lines @@
                                 # ebuild process if it is waiting for a reply
                                 # when we try to kill the ebuild process.
                                 reply_hook = getattr(cmd_handler,
                                         'reply_hook', None)
                                 if reply_hook is not None:
                                         reply_hook()
 
         def _send_reply(self, reply):
                 # File streams are in unbuffered mode since we do atomic
                 # read and write of whole pickles.
-                output_file = open(self.output_fifo, 'wb', 0)
-                output_file.write(pickle.dumps(reply))
-                output_file.close()
+                output_file = os.open(self.output_fifo, os.O_WRONLY | os.O_NONBLOCK)
+                os.write(output_file, pickle.dumps(reply))
+                os.close(output_file)