There's a merged pull request on the void-packages repository

[RFC] New numpy build_helper to support cross compilation
https://github.com/void-linux/void-packages/pull/23515

Description:
I plan on adding some packages that link against `python3-numpy` and require the same kinds of environment manipulations currently done in `python3-scipy` to support cross building. The new templates would be simplified if these manipulations were centralized in a build_helper, so here it is. `python3-scipy` has been reworked to take advantage of the new helper.