cc -O2 -pipe  -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations aio/union-sigval.c -o aio/union-sigval -D_POSIX_C_SOURCE=202405L  -lm -lpthread 
aio/union-sigval.c:1:10: fatal error: 'aio.h' file not found
#include <aio.h>
         ^~~~~~~
1 error generated.