Wheel depends on build-time numpy version
I've solved this issue to my satisfaction by adding a minimal 'pyproject.toml' with an exact pinned numpy version. This makes pip install in the the PEP 517 compliant build isolation mode where ONLY the dependencies listed in this file are installed.
[build-system]requires = ['numpy==1.12.2', 'setuptools>=40.8.0', 'wheel', 'packaging']build-backend = "setuptools.build_meta"My install_requires in my setup.py still lists numpy>=1.12.2 though, so when the produced wheel gets installed, pip will not (try to) forcefully downgrade numpy to 1.12.2 if for example 1.16.2 is already installed.