If you run python -m compileall on any of the wheels for the latest release ~40 minutes ago, it will fail with:
Compiling 'google/protobuf/service.py'...
*** Sorry: IndentationError: unindent does not match any outer indentation level (service.py, line 78)
I can confirm there appears to be a missing space, but I don't see that file (under that name or contents) checked in.