When enabling pickle as the result serializer and enabling gzip as the message compression, I get a consistent UnicodeDecodeError on this line since it is trying to decode bytes into UTF-8, which cannot be done. Removing this line makes everything work like a charm. It also works fine with JSON and JSON+GZIP.
Why was it inserted? What did it fix? Was there a change in python 3.3 that maybe makes it no longer necessary?