Two things have happened with Python: we switched bytes from 'text or binary' to 'binary (or text)' in 3.0. We switched from svn to hg in 3.2. When did test_sax start failing? I have no idea. Until recently, there were much worse problems with the test suite on desktop windows; it sometimes quit before getting to 'sax'.

Email and its tests (which had the same eol issue) were heavily revised in 3.3; I do not know if the test that failed in 3.3 failed earlier or not. Another failing email test was added in 3.4.

David, Antoine: Tim questions/challenges the solution pushed in #12037.