git commit efb7b9dec13 added ``` #ifndef HAVE__NSGETENVIRON /* FreeBSD needs this; it doesn't seem to hurt other platforms. */ extern char **environ; #endif ``` But on my Debian testing with --enable-gcc-warnings, I get ``` compat.c:1667:15: error: redundant redeclaration of ‘environ’ [-Werror=redundant-decls] /usr/include/unistd.h:542:15: note: previous declaration of ‘environ’ was here cc1: all warnings being treated as errors ```