darwin aarch64 skrf/calibration/tests/test_calibration.py failing with divide by zero (determinate calculations)

darwin aarch64 skrf/calibration/tests/test_calibration.py failing with divide by zero (determinate calculations)

on macos aarch64 this simplified code produces a divide by zero warning but runs fine on x64 linux -- similar to the failing unit tests above.

#!/usr/bin/env python3
import numpy as np
print(np.__version__)
a = np.array([[5.e-8+0.j, 1+0.j], [1+0.j, 5.e-8+0.j]])
print(a)
print(np.linalg.det(a))

./test.py
1.25.2
[[5.e-08+0.j 1.e+00+0.j]
 [1.e+00+0.j 5.e-08+0.j]]
/nix/store/rpdx49knxarbr4lmkwfi5l0461lyp6bd-python3-3.11.6-env/lib/python3.11/site-packages/numpy/linalg/linalg.py:2180: RuntimeWarning: divide by zero encountered in det
  r = _umath_linalg.det(a, signature=signature)
/nix/store/rpdx49knxarbr4lmkwfi5l0461lyp6bd-python3-3.11.6-env/lib/python3.11/site-packages/numpy/linalg/linalg.py:2180: RuntimeWarning: invalid value encountered in det
  r = _umath_linalg.det(a, signature=signature)

[pbsds]

note to future self: re-enable the failing test in nixpkgs if a fix is found

[FranzForstmayr]

This should be reported to https://github.com/numpy/numpy itself, but this probably related numpy/numpy#22025.

[FranzForstmayr]

Nevertheless we could modify the unit test slightly to avoid this issue. I'm afraid we are not able to find the root cause here.