Python 3.7 fails to build on OSX with 404

3.7.3 is not installed; attempting download
Downloading archive:
0.14s$ curl -sSf -o python-3.7.3.tar.bz2 ${archive_url}
curl: (22) The requested URL returned error: 404 
Unable to download 3.7.3 archive. The archive may not exist. Please consider a different version.

We don’t support Python builds on the Mac.