Define -DPython_FIND_VIRTUALENV=First in CMAKE_ARGS

[hmaarrfk]

Comment:

Would it make sense to define this?

it seemed that defining Pythin_FIND_VIRTUALENV helped in

https://github.com/conda-forge/openimageio-feedstock/pull/87

https://cmake.org/cmake/help/latest/module/FindPython.html

cc: @h-vetinari

[isuruf]

You should set Python3_FIND_STRATEGY=LOCATION. This is done by many feedstocks and I think it's somewhere in our docs.

[isuruf]

And also patch upstream projects to use https://cmake.org/cmake/help/latest/policy/CMP0094.html#policy:CMP0094

[hmaarrfk]

thanks

[hmaarrfk]

Reading this section was helpful to me: https://cmake.org/cmake/help/latest/manual/cmake-policies.7.html#introduction