Warning on Python 3.10/Ubuntu 22.04

[traversaro]

-- Found Python3: /usr/bin/python3.10 (found version "3.10.4") found components: Interpreter
<string>:1: DeprecationWarning: The distutils package is deprecated and slated for removal in Python 3.12. Use setuptools or check PEP 632 for potential alternatives
<string>:1: DeprecationWarning: The distutils.sysconfig module is deprecated, use sysconfig instead
<string>:1: DeprecationWarning: The distutils package is deprecated and slated for removal in Python 3.12. Use setuptools or check PEP 632 for potential alternatives
<string>:1: DeprecationWarning: The distutils.sysconfig module is deprecated, use sysconfig instead
<string>:1: DeprecationWarning: The distutils package is deprecated and slated for removal in Python 3.12. Use setuptools or check PEP 632 for potential alternatives
<string>:1: DeprecationWarning: The distutils.sysconfig module is deprecated, use sysconfig instead

[traversaro]

We should change all the places where we use:

from distutils import sysconfig; print(sysconfig.get_python_lib(1,0,prefix=''))

[traversaro]

Unfortunatly the sysconfig top module does not have the same functions of distutils.sysconfig, so the change is not as trivial as attempted in #1245 . I tried a more complex version from krshrimali/pytorch@361bce4, but unfortunatly it gives different results already in Ubuntu 22.04 :

traversaro@IITICUBLAP257:~$ python3 -c "from distutils import sysconfig; print(sysconfig.get_python_lib())"
<string>:1: DeprecationWarning: The distutils package is deprecated and slated for removal in Python 3.12. Use setuptools or check PEP 632 for potential alternatives
<string>:1: DeprecationWarning: The distutils.sysconfig module is deprecated, use sysconfig instead
/usr/lib/python3/dist-packages
traversaro@IITICUBLAP257:~$ python3 -c "import os;import sysconfig;relative_site_packages = sysconfig.get_path('purelib').replace(sysconfig.get_path('data'), '').lstrip(os.path.sep);print(relative_site_packages)"
lib/python3.10/dist-packages

So, we need to think more about this. Probably the best thing to do is not to rely subprojects of the superbuild to use the same logic of the superbuild to detect the python installation directly, but we should specify via appopriate CMake options the Python install directory used by the superbuild, so that we can change the Python libraries installation directory with no problem.

[traversaro]

This is required for Python 3.12 support, that is going to be released on October of 2023 .

[traversaro]

This is required for Python 3.12 support, that is going to be released on October of 2023 .

And October 2023 arrived!

[traversaro]

https://peps.python.org/pep-0632/

[traversaro]

Probably the best thing to do is not to rely subprojects of the superbuild to use the same logic of the superbuild to detect the python installation directly, but we should specify via appopriate CMake options the Python install directory used by the superbuild, so that we can change the Python libraries installation directory with no problem.

That is indeed the way to go. Once we do that, we can switch to the variant proposed in that comment, as changing the installation path (as long as they are both valid) would be perfectly ok.