opencv/cv2/opencvpython名称不匹配，如何说服pip不要寻找已经通过conda安装的包？

Question

python opencv绑定包含在conda forge上名为^{}的包或pypi上名为^{}的包中。在conda forge上安装opencv可以使用cv2模块。然而，在通过conda安装了这个包并根据opencv使用包之后，pip install找不到现有的包。根据包在setup.py中的调用，它要么搜索包却找不到，要么找到它并与conda版本一起安装

$ conda list | grep opencv
opencv                    4.1.0            py37h5517eff_4    conda-forge

如果setup.py中的名称是opencv，它将进行搜索（即使已经有一个opencv），但找不到：

$ pip install .
Processing /home/gholl/checkouts/fogpy
Requirement already satisfied: numpy>=1.16 in /media/nas/x21324/miniconda3/envs/py37d/lib/python3.7/site-packages (from fogpy==1.1.3+dev92.gb109242.temp) (1.16.2)
Requirement already satisfied: scipy>=1.2 in /media/nas/x21324/miniconda3/envs/py37d/lib/python3.7/site-packages (from fogpy==1.1.3+dev92.gb109242.temp) (1.2.1)
Requirement already satisfied: matplotlib>=1.4.2 in /media/nas/x21324/miniconda3/envs/py37d/lib/python3.7/site-packages (from fogpy==1.1.3+dev92.gb109242.temp) (3.0.3)
Requirement already satisfied: pyorbital>=1.5.0 in /media/nas/x21324/miniconda3/envs/py37d/lib/python3.7/site-packages (from fogpy==1.1.3+dev92.gb109242.temp) (1.5.0)
Requirement already satisfied: trollimage>=1.8.0 in /media/nas/x21324/miniconda3/envs/py37d/lib/python3.7/site-packages (from fogpy==1.1.3+dev92.gb109242.temp) (1.8.0)
Requirement already satisfied: satpy>=0.15 in /media/nas/x21324/miniconda3/envs/py37d/lib/python3.7/site-packages (from fogpy==1.1.3+dev92.gb109242.temp) (0.15.1+38.gc7161c08)
Requirement already satisfied: pyresample>=1.11 in /media/nas/x21324/miniconda3/envs/py37d/lib/python3.7/site-packages (from fogpy==1.1.3+dev92.gb109242.temp) (1.11.2)
Collecting opencv>=4.1 (from fogpy==1.1.3+dev92.gb109242.temp)
  Could not find a version that satisfies the requirement opencv>=4.1 (from fogpy==1.1.3+dev92.gb109242.temp) (from versions: )
No matching distribution found for opencv>=4.1 (from fogpy==1.1.3+dev92.gb109242.temp)

如果setup.py中的名称是opencv-python，它将在第一个模块旁边安装第二个opencv，并且导入cv2模块将导致未定义的符号错误

我怎样才能说服pip承认condas安装了opencv