py3: flush stdout This avoids buffering due to mixed print() and sys.stdout.write() by profiling code. And with this, test-profile.t passes on Python 3 \o/. Honestly, I'd be shocked if there weren't more Python 3 encoding issues lingering in the profiling code. That code isn't super high quality and doesn't seem to have thorough test coverage. Differential Revision: https://phab.mercurial-scm.org/D5018