System Information

• OS: Ubuntu 22.04.5 LTS (Jammy)
• Python Version: 3.10.12
• GCC Version: 11.4.0 (Ubuntu 11.4.0-1ubuntu1~22.04.2)
• Architecture: x86_64

OpenCV Build Details

• Source: Git repository (https://github.com/opencv/opencv)
• Commit Date: Latest commit as of 2025-11-07
• Build Method: CMake
• Compiler: gcc-11

Detailed description

Problem Description

After compiling OpenCV from the latest git master (as of 2025-11-07), the Python bindings fail to import with a syntax error in the typing stub file.

Error Output

  $ python3 -c "import cv2; print(cv2.__version__)"
  Traceback (most recent call last):
    File "<string>", line 1, in <module>
    File "/usr/local/lib/python3.10/dist-packages/cv2/__init__.py", line 181, in <module>
      bootstrap()
    File "/usr/local/lib/python3.10/dist-packages/cv2/__init__.py", line 175, in bootstrap
      if __load_extra_py_code_for_module("cv2", submodule, DEBUG):
    File "/usr/local/lib/python3.10/dist-packages/cv2/__init__.py", line 28, in __load_extra_py_code_for_module
      py_module = importlib.import_module(module_name)
    File "/usr/lib/python3.10/importlib/__init__.py", line 126, in import_module
      return _bootstrap._gcd_import(name[level:], package, level)
    File "/usr/local/lib/python3.10/dist-packages/cv2/typing/__init__.py", line 135
      cv::Vec2d = _typing.Sequence[float]
         ^
  SyntaxError: invalid syntax

Expected Behavior

OpenCV should import successfully without syntax errors.

Actual Behavior

Import fails immediately with a SyntaxError due to C++ namespace syntax (cv::) appearing in a Python file.

Steps to reproduce

CMake Configuration

cmake \
  -DCMAKE_BUILD_TYPE=RELEASE \
  -DCMAKE_INSTALL_PREFIX=/usr/local \
  -DCMAKE_C_FLAGS="-O2 -mtune=generic -ffunction-sections -fdata-sections" \
  -DCMAKE_CXX_FLAGS="-O2 -mtune=generic -ffunction-sections -fdata-sections -Wno-deprecated" \
  -DCMAKE_EXE_LINKER_FLAGS="-Wl,--gc-sections" \
  -DCMAKE_SHARED_LINKER_FLAGS="-Wl,--gc-sections" \
  -DENABLE_FAST_MATH=ON \
  -DWITH_OPENMP=ON \
  -DWITH_FFMPEG=ON \
  -DWITH_OPENCL=ON \
  -DWITH_CUDA=ON \
  -DWITH_TBB=ON \
  -DWITH_V4L=ON \
  -DBUILD_opencv_java=OFF \
  -DBUILD_TESTS=OFF \
  -DBUILD_PERF_TESTS=OFF \
  -DBUILD_EXAMPLES=OFF \
  -DBUILD_DOCS=OFF \
  -DBUILD_opencv_apps=OFF \
  -DWITH_QT=OFF \
  -DWITH_GTK=OFF \
  -DWITH_IPP=ON \
  -DCPU_BASELINE_DETECT=ON \
  -DCPU_BASELINE=SSE3 \
  -DCPU_DISPATCH=SSE4_1,SSE4_2,AVX,AVX2,AVX512_SKX,FP16 \
  ..

Steps to Reproduce

1. Clone OpenCV from git master (commit from around 2025-11-07)
2. Configure with CMake using the flags above
3. Build with make -j$(nproc)
4. Install with make install
5. Attempt to import: python3 -c "import cv2"

Edit: Manually editing /usr/local/lib/python3.10/dist-packages/cv2/typing/init.py to rename cv::Vec2d to Vec2d works around the problem.

Issue submission checklist

• I report the issue, it's not a question
• I checked the problem with documentation, FAQ, open issues, forum.opencv.org, Stack Overflow, etc and have not found any solution
• I updated to the latest OpenCV version and the issue is still there
• There is reproducer code and related data files (videos, images, onnx, etc)