CMake's 'find_host_package(PythonInterp 2.7)' founds wrong Python version:

[yaoganxingwei]

CMake Warning at cmake/OpenCVDetectPython.cmake:81 (message):
CMake's 'find_host_package(PythonInterp 2.7)' founds wrong Python version:

PYTHON_EXECUTABLE=D:/Program Files/python/python.exe

PYTHON_VERSION_STRING=3.8.1

Consider specify 'PYTHON2_EXECUTABLE' variable via CMake command line or
environment variables

Call Stack (most recent call first):
cmake/OpenCVDetectPython.cmake:271 (find_python)
CMakeLists.txt:595 (include)

[YannickJadoul]

Is this related to pybind11? I only see cmake/OpenCVDetectPython.cmake in your error message.
Can you give some more details/further explanation/minimal example that reproduces this error?

[henryiii]

OpenCV has a heavily modified FindPythonInterp/FindPythonLibs search, just like we do (only more extreme for them; they are adding brand new sets of variables like PYTHON2_EXECUTABLE, we just add a few variables). They are very unlikely to ever be compatible. You can try pybind11 first, and see if OpenCV is happy with that (probably not).

Otherwise, wait until #2370 and then use PYBIND11_NOPYTHON mode.

[henryiii]

PS: find_host_package is not a CMake command, it's probably something added by OpenCV.