There is a new pull request by ahesford against master on the void-packages repository

https://github.com/ahesford/void-packages musl-legacy-compat
https://github.com/void-linux/void-packages/pull/21882

musl-legacy-compat: add include guards to cdefs.h
The `cdefs.h` included in this package is missing include guards, breaking some software with sloppy includes that expects this file.

cc: @Gottox 

A patch file from https://github.com/void-linux/void-packages/pull/21882.patch is attached