detach io thread output from creation cell

Author: minrk

Diff for: ipyparallel/client/client.py

@@ -7,6 +7,7 @@
 import os
 import re
 import socket
+import sys
 import time
 import types
 import warnings
@@ -1078,6 +1079,13 @@ def _io_main(self, start_evt=None):
         """main loop for background IO thread"""
         self._io_loop = self._make_io_loop()
         self._setup_streams()
+
+        # disable ipykernel's association of thread output with the cell that
+        # spawned the thread.
+        # there should be a public API for this...
+        for stream in [sys.stdout, sys.stderr]:
+            if getattr(stream, "_thread_to_parent", None):
+                stream._thread_to_parent.pop(current_thread().ident, None)
         # signal that start has finished
         # so that the main thread knows that all our attributes are defined
         if start_evt: