New comment by ericonr on void-packages repository

https://github.com/void-linux/void-packages/pull/27936#issuecomment-760483854

Comment:
They should have `#define _POSIX_C_SOURCE` at the top of the file and before any `#include`, so `gmtime_r` would be exposed. Keeping their `#ifdef` forest would still work, I guess, but isn't really necessary. <-- this is a suggestion for a patch you should add