At the end of each error log, there is a message stating different python versions (up to 3.7) and AIX. However, there is no python3.8 + AIX, and there is no corresponding dependency:

ERROR: Command errored out with exit status 2:
   command: /Library/Frameworks/Python.framework/Versions/3.8/bin/python3.8 /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pip install --ignore-installed --no-user --prefix /private/tmp/pip-build-env-4mykinsd/overlay --no-warn-script-location --no-binary :none: --only-binary :none: -i https://pypi.org/simple <https://pypi.org/simple> -- wheel setuptools 'Cython>=0.29.2' 'numpy==1.13.3; python_version=='"'"'3.5'"'"' and platform_system!='"'"'AIX'"'"'' 'numpy==1.13.3; python_version=='"'"'3.6'"'"' and platform_system!='"'"'AIX'"'"'' 'numpy==1.14.5; python_version>='"'"'3.7'"'"' and platform_system!='"'"'AIX'"'"'' 'numpy==1.16.0; python_version=='"'"'3.5'"'"' and platform_system=='"'"'AIX'"'"'' 'numpy==1.16.0; python_version=='"'"'3.6'"'"' and platform_system=='"'"'AIX'"'"'' 'numpy==1.16.0; python_version>='"'"'3.7'"'"' and platform_system=='"'"'AIX'"'"''
       cwd: None

> On 4 Sep 2019, at 17:09, Mark Dickinson <report@bugs.python.org> wrote:
> 
> pip install git+https://github.com/numpy/numpy.git <git+https://github.com/numpy/numpy.git%60>