cc -O2 -pipe  -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations pthread/PTHREAD_MUTEX_ROBUST.c -o pthread/PTHREAD_MUTEX_ROBUST -D_POSIX_C_SOURCE=202405L  -lm -lpthread 
pthread/PTHREAD_MUTEX_ROBUST.c:2:17: error: use of undeclared identifier 'PTHREAD_MUTEX_ROBUST'; did you mean 'PTHREAD_MUTEX_NORMAL'?
int const foo = PTHREAD_MUTEX_ROBUST;
                ^~~~~~~~~~~~~~~~~~~~
                PTHREAD_MUTEX_NORMAL
/usr/include/pthread.h:171:2: note: 'PTHREAD_MUTEX_NORMAL' declared here
        PTHREAD_MUTEX_NORMAL            = 3,    /* No error checking */
        ^
1 error generated.