cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations unistd/getresgid.c -o unistd/getresgid -D_POSIX_C_SOURCE=202405L  -lm -lpthread  -liconv
unistd/getresgid.c:11:65: error: use of undeclared identifier 'getresgid'
   11 | int (*foo)(gid_t *restrict, gid_t *restrict, gid_t *restrict) = getresgid;
      |                                                                 ^
1 error generated.