ubuntu20.04下，在c++中调用python代码时，编译遇到以下错误：

/usr/bin/ld: /lib/x86_64-linux-gnu/libgobject-2.0.so.0: undefined reference to ffi_type_uint32@LIBFFI_BASE_7.0' /usr/bin/ld: /lib/x86_64-linux-gnu/libgobject-2.0.so.0: undefined reference toffi_type_sint32@LIBFFI_BASE_7.0’
/usr/bin/ld: /lib/x86_64-linux-gnu/libgobject-2.0.so.0: undefined reference to ffi_type_float@LIBFFI_BASE_7.0' /usr/bin/ld: /lib/x86_64-linux-gnu/libgobject-2.0.so.0: undefined reference toffi_type_pointer@LIBFFI_BASE_7.0’
/usr/bin/ld: /lib/x86_64-linux-gnu/libgobject-2.0.so.0: undefined reference to ffi_type_uint64@LIBFFI_BASE_7.0' /usr/bin/ld: /lib/x86_64-linux-gnu/libgobject-2.0.so.0: undefined reference toffi_type_void@LIBFFI_BASE_7.0’
/usr/bin/ld: /lib/x86_64-linux-gnu/libgobject-2.0.so.0: undefined reference to ffi_type_double@LIBFFI_BASE_7.0' /usr/bin/ld: /lib/x86_64-linux-gnu/libgobject-2.0.so.0: undefined reference toffi_type_sint64@LIBFFI_BASE_7.0’
/usr/bin/ld: /lib/x86_64-linux-gnu/libgobject-2.0.so.0: undefined reference to ffi_prep_cif@LIBFFI_BASE_7.0' /usr/bin/ld: /lib/x86_64-linux-gnu/libgobject-2.0.so.0: undefined reference toffi_call@LIBFFI_BASE_7.0’

根据这篇文章Conda虚拟环境下libp11-kit.so.0: undefined symbol: ffi_type_pointer…问题解决的操作，解决了编译问题。步骤如下：

1. 找到所使用的python环境，进到它的lib下，比如我的是~/miniconda3/envs/py38/lib
2. cd ~/miniconda3/envs/py38/lib
3. 查看：ll | grep libffi
   
4. 备份：mv libffi.so.7 libffi.so.7-bak
5. 重新链接：ln -s /lib/x86_64-linux-gnu/libffi.so.7.1.0 libffi.so.7
6. 结果
   

但我还遇到另一个大坑：运行时仍然报错！折腾了我好久，原来是c++的opnecv版本跟python的opencv-python不一致导致的，解决就是尽量让opencv版本和opencv-python版本保持一致。

1. /usr/local/bin/opencv_version

3.4.15

2. python3 -c "import cv2; print(cv2.__version__)"

3.4.15