cc -O2 -pipe -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations sys_wait/waitid.c -o sys_wait/waitid -D_POSIX_C_SOURCE=202405L  -lm -lpthread -lrt  -lstdthreads -lcrypt
sys_wait/waitid.c:5:28: error: unknown type name 'siginfo_t'
    5 | int (*foo)(idtype_t, id_t, siginfo_t *, int) = waitid;
      |                            ^
sys_wait/waitid.c:5:7: error: incompatible function pointer types initializing 'int (*)(idtype_t, id_t, int *, int)' (aka 'int (*)(idtype_t, long, int *, int)') with an expression of type 'int (idtype_t, id_t, struct __siginfo *, int)' (aka 'int (idtype_t, long, struct __siginfo *, int)') [-Wincompatible-function-pointer-types]
    5 | int (*foo)(idtype_t, id_t, siginfo_t *, int) = waitid;
      |       ^                                        ~~~~~~
2 errors generated.