What’s new in PyPy3 7.3.1

Make cpyext test faster, especially on py3.6

Follow CPython’s behaviour more closely in sqlite3

Improve performance of io.StringIO(). It should now be faster than CPython in common use cases.

virtualenv on macOS defines an environment variable __PYVENV_LAUNCHER__ to let the invoked python know it is inside a venv. This is not needed on PyPy so it is deleted when importing site and reset afterwards.