[Bug]: PGF backend crashes at program exit after creating a plot #27437
Description
Bug summary
After successfully creating a plot using the PGF backend, Python will crash on exit while running cleanup code.
Code for reproduction
import matplotlib
matplotlib.use("pgf")
import matplotlib.pyplot as plt
fig, ax = plt.subplots(1, 1)
ax.plot(list(range(100)), [x * 2 for x in range(100)])
fig.savefig("test.pgf", format="pgf")Actual outcome
Two exceptions are produced at exit. The first is:
Traceback (most recent call last):
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\weakref.py", line 666, in _exitfunc
f()
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\weakref.py", line 590, in __call__
return info.func(*info.args, **(info.kwargs or {}))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\Anon\Desktop\Projects\mplbug\venv\Lib\site-packages\matplotlib\backends\backend_pgf.py", line 277, in finalize_latex
latex.communicate()
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\subprocess.py", line 1209, in communicate
stdout, stderr = self._communicate(input, endtime, timeout)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\subprocess.py", line 1610, in _communicate
self.stdout_thread.start()
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\threading.py", line 971, in start
_start_new_thread(self._bootstrap, ())
RuntimeError: can't create new thread at interpreter shutdown
The second, which will not be produced if time elapses between plot creation and program exit (read: a sleep(0.5) call), is:
Traceback (most recent call last):
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\shutil.py", line 634, in _rmtree_unsafe
os.unlink(fullname)
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'C:\\Users\\Anon\\AppData\\Local\\Temp\\tmp4qorphqa\\texput.aux'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\tempfile.py", line 891, in onexc
_os.unlink(path)
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'C:\\Users\\Anon\\AppData\\Local\\Temp\\tmp4qorphqa\\texput.aux'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\weakref.py", line 666, in _exitfunc
f()
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\weakref.py", line 590, in __call__
return info.func(*info.args, **(info.kwargs or {}))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\tempfile.py", line 923, in cleanup
self._rmtree(self.name, ignore_errors=self._ignore_cleanup_errors)
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\tempfile.py", line 903, in _rmtree
_shutil.rmtree(name, onexc=onexc)
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\shutil.py", line 796, in rmtree
return _rmtree_unsafe(path, onexc)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\shutil.py", line 636, in _rmtree_unsafe
onexc(os.unlink, fullname, err)
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\tempfile.py", line 894, in onexc
cls._rmtree(path, ignore_errors=ignore_errors)
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\tempfile.py", line 903, in _rmtree
_shutil.rmtree(name, onexc=onexc)
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\shutil.py", line 796, in rmtree
return _rmtree_unsafe(path, onexc)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\shutil.py", line 612, in _rmtree_unsafe
onexc(os.scandir, path, err)
File "C:\Users\Anon\AppData\Local\Programs\Python\Python312\Lib\shutil.py", line 609, in _rmtree_unsafe
with os.scandir(path) as scandir_it:
^^^^^^^^^^^^^^^^
NotADirectoryError: [WinError 267] The directory name is invalid: 'C:\\Users\\Anon\\AppData\\Local\\Temp\\tmp4qorphqa\\texput.aux'
Expected outcome
No crashes.
Additional information
Workaround that prevents both exceptions is running weakref.finalize._exitfunc() before program exit.
Workaround that prevents the second exception only is letting time elapse before program exit (like with a time.sleep(0.5) call).
Operating system
Windows 11 Enterprise 22H2
Matplotlib Version
3.8.2
Matplotlib Backend
pgf
Python version
3.12.0
Jupyter version
No response
Installation
pip