New comment by tornaria on void-packages repository

https://github.com/void-linux/void-packages/pull/46109#issuecomment-1726817020

Comment:
Here's a first proof of concept of fixing cross build for contourpy (see also: #46117).

Summary:
 1. there is a post-patch hook which will create a meson cross file in `$meson_crossfile` if that variable is set.
 2. the template for `python3-contourpy` will, if cross building, set `meson_crossfile=$wrksrc/xbps_meson.cross` to instruct the hook to create the crossfile; and it also sets `make_build_args=--config-setting=setup-args=--cross-file=$meson_crossfile` so the crossfile gets passed to meson
 3. note that I had to change the `python3-pep517" build-style so the `make_build_args` variable is usable.