https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117857
--- Comment #15 from Gleb Mazovetskiy <glex.spb at gmail dot com> --- Also in macports, there is only one use of `-D_APPLE_C_SOURCE` in macports, for the tmux package. https://github.com/macports/macports-ports/blob/ad9460ffa5b5ff8ce8e7b4e3dd01cf7db07dac8c/sysutils/tmux/Portfile#L80-L83
