Importing zarr in app packaged by pyinstaller continually restarts the script

[pearcetm]

Zarr version

v2.17.0

Numcodecs version

v0.12.1

Python Version

3.10

Operating System

Mac

Installation

using pip into virtual environment

Description

Within an application built by pyinstaller, the application keeps getting recursively run somehow. I'm not sure whether this is best considered a pyinstaller problem or a zarr problem, but zarr is the only library I've seen this happen with so far. I am looking for ideas on what could be causing this behavior.

Steps to reproduce

In test.py

import zarr
print('Starting test.py')
print(zarr)
print('Exiting')

On the command line (in your virtual env)

pip install zarr
pip install pyinstaller
python -m PyInstaller test.py

Running python test.py gives the following:

Running dist/test/test (built by pyinstaller) leads to this:

Ctrl-c in the command window doesn't kill the loop, though it appears it can kill individual processes as they scroll by.

Additional output

No response

[pearcetm]

Did some more searching. Following this stack overflow answer fixes this issue.

Adding this to the beginning of my script stopped the behavior described above.

import multiprocessing
multiprocessing.set_start_method('forkserver', force=True)
multiprocessing.freeze_support()

So, not a zarr problem after all.