Matplotlib (Python) totally broken on UCRT64 (at least)

[angelog0]

Description / Steps to reproduce the issue

Given:

$ cat plot_test.py
import matplotlib.pyplot as plt
import numpy as np

t = np.arange(0.0, 1.0 + 0.01, 0.01)
s = np.cos(2*2*np.pi*t)
plt.plot(t, s, '-', lw=2)

plt.xlabel('time (s)')
plt.ylabel('voltage (mV)')
plt.title('About as simple as it gets, folks')
plt.grid(True)

plt.axes().set_aspect('equal', 'datalim')


plt.show()

one gets

$ python plot_test.py
Traceback (most recent call last):
  File "C:/msys64/tmp/plot_test.py", line 1, in <module>
    import matplotlib.pyplot as plt
  File "C:/msys64/ucrt64/lib/python3.12/site-packages/matplotlib/__init__.py", line 159, in <module>
    from . import _api, _version, cbook, _docstring, rcsetup
  File "C:/msys64/ucrt64/lib/python3.12/site-packages/matplotlib/rcsetup.py", line 28, in <module>
    from matplotlib.colors import Colormap, is_color_like
  File "C:/msys64/ucrt64/lib/python3.12/site-packages/matplotlib/colors.py", line 57, in <module>
    from matplotlib import _api, _cm, cbook, scale
SyntaxError: source code string cannot contain null bytes

Expected behavior

It should open a window with a plot.

Actual behavior

It prints errors

Verification

• I have verified that my MSYS2 is up-to-date before submitting the report (see https://www.msys2.org/docs/updating/)

Windows Version

MINGW64_NT-10.0-19045

MINGW environments affected

• MINGW64
• MINGW32
• UCRT64
• CLANG64
• CLANGARM64

Are you willing to submit a PR?

No response

[podsvirov]

It's work for me as expected but only after commenting one line:

#plt.axes().set_aspect('equal', 'datalim')

[angelog0]

But all python scripts using matplotlib I have, worked until two months ago.. the above too... Now none work...

[lazka]

It's work for me as expected but only after commenting one line:

#plt.axes().set_aspect('equal', 'datalim')

same here

[angelog0]

This is another example taken from here:

$ cat logistic_map.py
import numpy as np
import matplotlib.pyplot as plt

interval = (2.8, 4)  # start, end
accuracy = 0.0001
reps = 600  # number of repetitions
numtoplot = 200
lims = np.zeros(reps)

fig, biax = plt.subplots()
fig.set_size_inches(16, 9)

lims[0] = np.random.rand()
for r in np.arange(interval[0], interval[1], accuracy):
    for i in range(reps - 1):
        lims[i + 1] = r * lims[i] * (1 - lims[i])

    biax.plot([r] * numtoplot, lims[reps - numtoplot :], "b.", markersize=0.02)

biax.set(xlabel="r", ylabel="x", title="logistic map")
plt.show()

On WSL I have

$ python3 --version
Python 3.12.3

$ python3 logistic_map.py

and the image shows up.

On MSYS2/UCRT64:

$ python3 --version
Python 3.12.7

$ python3 logistic_map.py
Traceback (most recent call last):
  File "C:/msys64/home/angelo/programming/circle_3p/logistic_map.py", line 2, in <module>
    import matplotlib.pyplot as plt
  File "C:/msys64/ucrt64/lib/python3.12/site-packages/matplotlib/__init__.py", line 159, in <module>
    from . import _api, _version, cbook, _docstring, rcsetup
  File "C:/msys64/ucrt64/lib/python3.12/site-packages/matplotlib/rcsetup.py", line 28, in <module>
    from matplotlib.colors import Colormap, is_color_like
  File "C:/msys64/ucrt64/lib/python3.12/site-packages/matplotlib/colors.py", line 57, in <module>
    from matplotlib import _api, _cm, cbook, scale
SyntaxError: source code string cannot contain null bytes

[lazka]

Does pacman -Qkk mingw-w64-ucrt-x86_64-python-matplotlib give any errors? (checking if all files are unaltered)