Linux VTK Build error: The version of Python is unknown


I’m attempting to do a VTK build using the source within the ParaView 5.8.1-RC1
source download. I’m encountering several errors, but I’ll stick with one per
discussion thread. I’m building on “CentOS Linux release 8.2.2004”.

Probably the one that needs to be addressed first is regarding an unknown Python
version message (“The version of Python is unknown; not using a versioned directory
for Python modules.”)

I’ve set VTK_PYTHON_VERSION to “3”, and CMake is finding the library and
include files:
Python3_LIBRARY_RELEASE /usr/lib64/
_Python3_INCLUDE_DIR /usr/include/python3.6m
_Python3_LIBRARY_RELEASE /usr/lib64/

But it also says:
Python3_DIR Python3_DIR-NOTFOUND

And finally, I should point out that the 'generate" option is available, so
maybe this is an innocuous message, but I get it everytime I do a
“configure”, so it seems like something that should be addressed.

Suggestions welcome.

I think this was eventually fixed. IIRC, the wrong variables had been used to detect the Python version number for the lib/pythonX.Y/site-packages directory.