cc -pthread   -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations semaphore/O_EXCL.c -o semaphore/O_EXCL -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt  -lgdbm_compat -lcrypt -latomic
semaphore/O_EXCL.c:3:2: error: #error "O_EXCL is not defined"
    3 | #error "O_EXCL is not defined"
      |  ^~~~~