cc -pthread -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations pthread/PTHREAD_CANCEL_DEFERRED.c -o pthread/PTHREAD_CANCEL_DEFERRED -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -lintl -liconv pthread/PTHREAD_CANCEL_DEFERRED.c:2:17: error: ‘PTHREAD_CANCEL_DEFERRED’ undeclared here (not in a function) 2 | int const foo = PTHREAD_CANCEL_DEFERRED; | ^~~~~~~~~~~~~~~~~~~~~~~