ipython/ipython — pull request #4214 by minrk (2013-09-15 18:28:51+00:00)
Title: engine ID metadata should be unicode, not bytes

fixes `TypeError: b'f5b984b0-fd8c-4873-a23e-658425c1e28a' is not JSON serializable` when an engine dies while working on a task in Python 3.

candidate for backport to 1.2