[CMake] FIX pybind11 finding python (2)

[guparan]

TO BE SQUASHED

I thought PYTHON_EXECUTABLE was enough but apparently it's not with pybind11 2.4.3

See error in https://ci.inria.fr/sofa-ci-dev/job/sofa-framework/job/master/CI_CONFIG=ubuntu_clang-6,CI_PLUGINS=options,CI_TYPE=release/2758/consoleFull

[guparan]

PR tested successfully on
CentOS: https://ci.inria.fr/sofa-ci-dev/job/sofa-custom/1756/CI_CONFIG=centos_clang-5,CI_TYPE=release/consoleFull
Ubuntu: https://ci.inria.fr/sofa-ci-dev/job/sofa-custom/1756/CI_CONFIG=ubuntu_clang-6,CI_TYPE=release/consoleFull

[jnbrunet]

CI here is not happy :-(

[guparan]

cannot find -lpython3.7m
Why that? 😭

[guparan]

With my latest commit, SOFA CI will fail

--- find_package(Python) ---
-- Found Python: /usr/bin/python3.7 (found suitable version "3.7.5", minimum required is "3.7") found components:  Interpreter Development 
--- find_package(Python) done ---
--- find_package(pybind11) ---
-- Found PythonInterp: /usr/bin/python3.7 (found suitable version "3.7.5", minimum required is "3.7") 
-- Found PythonLibs: /usr/lib/python2.7/config-x86_64-linux-gnu/libpython2.7.so
--- find_package(pybind11) done ---

PythonLibs should not be python 2.7

[guparan]

We should be good now @jnbrunet 👍

[jnbrunet]

Hey @guparan

Looks like the tests are failing on MacOS because numpy cannot be found. Numpy is installed as a requirement so this sounds like numpy as been installed on a python version different from the one used for the compilation. Does that rings a bell?

[guparan]

SOFA minimal binaries do not include SP3 anymore but the workflows are fetching an old (always the same) version of the binaries. Maybe this is the cause?
If yes, #157 should solve that.

[jnbrunet]

Hum here the tests are running using the SP3 built previously in the same workflow, not the one downloaded from SOFA.

Looking quickly over your workflow result:

1. SP3 cmake shows that python 3.9 is used for building, even tho we set up version 3.7 for the job....
2. SP3 test job is setting python to version 3.7, and is using this python version to download numpy

I'm not sure why python 3.9 is used here for the build job... It wasn't before your changes apparently. It seems to be ok on Linux however (3.7 is used both for building and testing).

[guparan]

@jnbrunet I'm done here too! Debug logs could be removed but it can wait another PR.
Let's merge, SOFA CI has been waiting this fix for too long!

[jnbrunet]

All good here, if you could just resolve the conflicts (I just merged #157) , I'll merge as soon as its done

[guparan]

Done 👌