clang -O2 -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations unistd/_POSIX_THREAD_SPORADIC_SERVER.c -o unistd/_POSIX_THREAD_SPORADIC_SERVER -D_POSIX_C_SOURCE=202405L -lm -lintl unistd/_POSIX_THREAD_SPORADIC_SERVER.c:4:2: error: "_POSIX_THREAD_SPORADIC_SERVER is not defined" #error "_POSIX_THREAD_SPORADIC_SERVER is not defined" ^ 1 error generated.