cc -O2 -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations unistd/_XOPEN_REALTIME.c -o unistd/_XOPEN_REALTIME -D_POSIX_C_SOURCE=202405L  -lm -lpthread -lrt  -lintl -lcrypt
unistd/_XOPEN_REALTIME.c:9:2: error: #error "_XOPEN_REALTIME is not defined"
    9 | #error "_XOPEN_REALTIME is not defined"
      |  ^~~~~