gcc -pthread   -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations unistd/_XOPEN_UUCP.c -o unistd/_XOPEN_UUCP -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -lxnet  -lsocket -latomic
unistd/_XOPEN_UUCP.c:4:2: error: #error "_XOPEN_UUCP is not defined"
    4 | #error "_XOPEN_UUCP is not defined"
      |  ^~~~~