warning: implicit declaration of function 'send' is invalid in C99
There's obviously a missing include:
work/pulseaudio-13.0/src/pulsecore/core-util.c:439:22: warning: implicit declaration of function 'send' is invalid in C99 [-Wimplicit-function-declaration]
if ((r = send(fd, buf, count, MSG_NOSIGNAL)) < 0) {
^
pulseaudio-13.0 FreeBSD 12.2