cc -O2 -pipe  -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations stdlib/WNOHANG.c -o stdlib/WNOHANG -D_POSIX_C_SOURCE=202405L  -lm -lpthread 
stdlib/WNOHANG.c:2:17: error: use of undeclared identifier 'WNOHANG'
int const foo = WNOHANG;
                ^
1 error generated.