There is an updated pull request by tornaria against master on the void-packages repository

https://github.com/tornaria/void-packages gfan
https://github.com/void-linux/void-packages/pull/34182

New package: gfan-0.6.2
Dependency of sagemath

A patch file from https://github.com/void-linux/void-packages/pull/34182.patch is attached