python3-mesonpy (Meson Python build backend, PEP517)

meson-python is a Python build backend built on top of the Meson build
system. It enables to use Meson for the configuration and build steps
of Python packages.

NOTE: Does not work with the stock 15.0 meson.

PYTHONPATH needs to be set to use python3-meson-opt.

PYVER=$(python3 -c 'import sys; print("%d.%d" % sys.version_info[:2])')
export PYTHONPATH=/opt/python$PYVER/site-packages