cv2 import error when using OpenCV built from source

[pwuertz]

When pyinstalling an application with an OpenCV-built-from-source dependency, the bundled application fails importing cv2 with an error message like this:

ImportError: OpenCV loader: missing configuration file: ['config.py']. Check OpenCV installation.

This problem exists on Linux and Windows alike (also reported and discussed in pyinstaller/pyinstaller#4564).

I think the issue is specific to OpenCV built and installed from source, which installs some sort of dynamic loader for importing the real cv2 so/pyd module. Workarounds presented so far circumvent this problem by adding the real module path as pythonpath with high priority, thus bypassing the loader.

The python module layout created by OpenCV source builds looks like this:

./dist-packages
./dist-packages/cv2
./dist-packages/cv2/python-3.9
./dist-packages/cv2/python-3.9/cv2.cpython-39-x86_64-linux-gnu.so
./dist-packages/cv2/__init__.py
./dist-packages/cv2/__pycache__
./dist-packages/cv2/__pycache__/__init__.cpython-39.pyc
./dist-packages/cv2/__pycache__/load_config_py3.cpython-39.pyc
./dist-packages/cv2/load_config_py2.py
./dist-packages/cv2/config.py
./dist-packages/cv2/load_config_py3.py
./dist-packages/cv2/config-3.9.py

And here is the top level import script doing all sorts of library path manipulation before selecting and loading the real module dynamically: init.py

Is there something that can be done at hook-cv2.py to mitigate this problem? PyInstaller already provides all the magic for resolving and bundling .dll/.so dependencies, so in general it should be safe to skip the OpenCV loader altogether as shown by the workarounds. Is there a way to import cv2 within hook-cv2.py, and then tell PyInstaller to just package the module cv2 points to instead of trying to analyze the cv2/ module dir?

[jmspereira]

There is any news regarding this issue? I think that this problem is the same that occurs with new opencv version.

[shagren]

There is any news regarding this issue? I think that this problem is the same that occurs with new opencv version.

Confirmed. Latest version opencv having same problem. Before problem didn't reproduced.

[IvanLauLinTiong]

I'm also facing this problem with the latest versions:
PyInstaller 4.6
opencv-python 4.5.3.58

For temporary workaround, I downgraded opencv version to 4.5.3.56. and It's working fine with PyInstaller 4.6 .

[rokm]

Yeah, it looks like that horrible loader shim made it into wheels. I was hoping this was an oversight, but opencv/opencv-python#569 seems to suggest this was intentional (even though as far as I can tell, the library search path magic is largely redundant (especially compared to what were doing before) as wheels are statically linked against OpenCV, so the library path they are trying to set does not exist).

But even if we were to collect those config scripts, the module swapping trick module does not work with PyInstaller at the moment, presumably because our FrozenImporter is immune to changes to sys.path, so it always loads the collected cv2/__init__.py wrapper (from PYZ), leading to recursion error. I suppose we'll have to modify it to give precedence to on-filesystem files (or at least binary extensions), or maybe try to put it at the end of sys.meta_path so that on-filesystem resources are handled first using the built-in loaders/importers.

[ns1998-hub]

I'm also facing this problem with the latest versions: PyInstaller 4.6 opencv-python 4.5.3.58

For temporary workaround, I downgraded opencv version to 4.5.3.56. and It's working fine with PyInstaller 4.6 .

I also tried with downgrade the version but still getting same error, ImportError: OpenCV loader: missing configuration file: ['config.py']. Check OpenCV installation.

[adh-arsh]

I'm also facing this problem with the latest versions: PyInstaller 4.6 opencv-python 4.5.3.58
For temporary workaround, I downgraded opencv version to 4.5.3.56. and It's working fine with PyInstaller 4.6 .

I also tried with downgrade the version but still getting same error, ImportError: OpenCV loader: missing configuration file: ['config.py']. Check OpenCV installation.

Downgrading only opencv-python to 4.5.3.56 worked for me.