GitHub Actions: 2D Fourier mapping tests inconsistent on macOS and Linux

[paulmueller]

This issue can be reproduced for very specific python versions and so far happens consistently only on specific CI runs.

It must have something to do with the environment. Python packages on GH Actions are all from PyPI...

import numpy as np
import pathlib
import matplotlib.pylab as plt

paths = ["data_expected.txt", "data_curious.txt"]

data = [np.loadtxt(f) for f in paths]


p1 = data[0].view(complex).reshape(22, 22)
p2 = data[1].view(complex).reshape(22, 22)


ax1 = plt.subplot(221, title="expected real")
ax1.imshow(p1.real)

ax2 = plt.subplot(222, title="expected imag")
ax2.imshow(p2.real)

ax3 = plt.subplot(223, title="diff real")
ax3.imshow(p2.real - p1.real)

ax4 = plt.subplot(224, title="diff imag")
ax4.imshow(p2.imag- p1.imag)

plt.show()

[paulmueller]

data_.zip

[paulmueller]

This test passes on my local Linux machine, but on GitHub Actions, it most often fails...