--- Modules/selectmodule.o ---
./Modules/selectmodule.c:703:23: error: call to undeclared function 'ppoll'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration]
  703 |         poll_result = ppoll(self->ufds, self->ufd_len, ts_p, NULL);
      |                       ^
./Modules/selectmodule.c:703:23: note: did you mean 'poll'?
/usr/include/poll.h:117:5: note: 'poll' declared here
  117 | int     poll(struct pollfd _pfd[], nfds_t _nfds, int _timeout);
      |         ^
1 error generated.

checking for ppoll... yes
...
checking for sys/poll.h... yes