f2py works with legacy Fortran 77 code, but generally does not work with modern Fortran code. Projects should carefully consider alternative approaches to f2py, such as a command-line + file interface with Python.

If experiencing compiler errors when using f2py, a last resort workaround is finding another computer that the install works on, of the same operating system. This can work on Windows or Linux from a computer of the same operating system and compiler ABI.

On the “donor” working computer:

python -m build

This creates mypkg/dist/mypkg-x.y.z-cp3x-cp3xm-win_amd64.whl (similar for other OS). This can only be used on Python 3.x (as per the filename) and the same CPU architecture.

python -m pip install -e .

This creates mypkg/src/mypkgy/fortranmodule.cp3x-win_amd64.pyd

Recipient computer: both of those files are copied from the “donor” computer to the “recipient” computer. The *.pyd file is placed or soft-linked to the Python current working directory. The *.whl file is one-time installed by:

python -m pip install mypkg-x.y.z-cp3x-cp3xm-win_amd64.whl