cc -pipe -O   -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations termios/CR2.c -o termios/CR2 -D_POSIX_C_SOURCE=202405L  -lm -lpthread -lrt  -lrt -lcrypt
termios/CR2.c:8:17: error: 'CR2' undeclared here (not in a function)
 int const foo = CR2;
                 ^~~