CMake requires libpythonXX.a

[pitrou]

Not sure it's worth fixing here, but it seems that when using:

find_package(Python3 COMPONENTS Interpreter Development REQUIRED)

the "Development" component fails being found if libpythonXX.a and libpythonXX.so both cannot be found. This is a problem when building C extensions using CMake (rather than using setuptools).

Note that the library isn't actually used for building (you can touch the missing file and it makes CMake happy), but it's required to be present anyway...

(see CMake docs)

[pitrou]

Also opened an issue against CMake: https://gitlab.kitware.com/cmake/cmake/issues/20425

[mayeut]

@pitrou,
it seems the bug you opened over at CMake has been fixed.
Can you confirm it's working please (or do we need to wait for CMake 3.18.0) ?

[pitrou]

I think this is going to wait for CMake 3.18.0. I don't see any mention of a backport in the CMake issue or PR.

[mayeut]

@pitrou,

CMake 3.18 is now available.
Can you confirm it's working please ?

[pitrou]

Sorry for the delay. I've tried CMake 3.18.2 and it does fix the issue, thank you.

[robtaylor]

just a note for anyone hitting this issue - you need to use Development.Module. This does the correct thing of not needing python libraries when building a module.