What do to, when pyinstaller sys._MEIPASS does not work?

Here is an example, which in fact works, and so it does not actually illustrate my problem, but just to set a basis for discussion:

mkdir C:/test/testpyinstcd C:/test/testpyinst

Here I have main.py:

#!/usr/bin/env python3import sys, osfrom lib import relative_path2def relative_path(relative_path): # https://stackoverflow.com/q/58487122  try:    base_path = sys._MEIPASS    print("_MEIPASS OK {}".format(base_path))  except Exception:    base_path = os.path.abspath(".")    print("_MEIPASS exception {}".format(base_path))  return os.path.join(base_path, relative_path)def main():  print("Hello from main")  print("relative_path {}".format(relative_path(".")))  print("relative_path2 {}".format(relative_path2(".")))if __name__ == '__main__':  main()

... and lib.py:

import sys, osdef relative_path2(relative_path): # https://stackoverflow.com/q/58487122  try:    base_path = sys._MEIPASS    print("_MEIPASS OK {}".format(base_path))  except Exception:    base_path = os.path.abspath(".")    print("_MEIPASS exception {}".format(base_path))  return os.path.join(base_path, relative_path)

I use this - pyinstaller installed via python3 -m pip install pyinstaller:

$ uname -sMINGW64_NT-10.0-19045$ python3 --versionPython 3.11.8$ pyinstaller --version6.5.0

When I run this code directly from python, _MEIPASS is as expected not accessible:

$ python3 main.pyHello from main_MEIPASS exception C:/test/testpyinstrelative_path C:/test/testpyinst/._MEIPASS exception C:/test/testpyinstrelative_path2 C:/test/testpyinst/.

Then I create an .exe with PyInstaller:

pyinstaller --onefile main.py

... and when I run the .exe, as expected, _MEIPASS works:

$ ./dist/main.exeHello from main_MEIPASS OK D:\msys64\tmp\_MEI199762relative_path D:\msys64\tmp\_MEI199762/._MEIPASS OK D:\msys64\tmp\_MEI199762relative_path2 D:\msys64\tmp\_MEI199762/.

So, here is my problem - in my actual (pyqt5) project, sys._MEIPASS does not work - in the sense that I always get an exception in relative_path() when trying to read sys._MEIPASSwhile running from the final .exe created by PyInstaller !?

I found this AttributeError: 'module' object has no attribute '_MEIPASS' (redux) · Issue #1785 · pyinstaller/pyinstaller:

sys._MEIPASS is set by the exe produced by pyinstaller before it runs any python code. I can think of a few reasons why it would not be set:

• The code reload(sys) is executed
• You are using a version of PyInstaller prior to 3.0
• PyInstaller was improperly installed and is using the old 2.1 bootloader files

I have tried running python3 -m trace --trace myprogram.py | grep reload, and apparently reload(sys) is never called in my program ...

So, I am still at a loss: what can I possibly do in my project, to get sys._MEIPASS working as expected?