cc -O2 -pipe -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations fcntl/F_SETOWN_EX.c -o fcntl/F_SETOWN_EX -D_POSIX_C_SOURCE=202405L  -lm -lpthread -lrt  -lstdthreads -lcrypt
fcntl/F_SETOWN_EX.c:3:2: error: "F_SETOWN_EX is not defined"
    3 | #error "F_SETOWN_EX is not defined"
      |  ^
1 error generated.