cc -O2 -pipe -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations termios/FF1.c -o termios/FF1 -D_POSIX_C_SOURCE=202405L  -lm -lpthread -lrt  -lstdthreads -lcrypt
termios/FF1.c:8:17: error: use of undeclared identifier 'FF1'
    8 | int const foo = FF1;
      |                 ^
1 error generated.