Ahem! The problem is not the NULL array start address. It's the array length being zero, and thus equal to the number of file descriptors that poll() fails to

Ahem! The problem is not the NULL array start address. It's the array length being zero, and thus equal to the number of file descriptors that poll() fails to add to the kqueue, also zero. Read everything referenced by the headlined article, and you'll find this.