How to find why php72_fpm is failing to start on OpenBSD?

My httpd logs show errors that look like php-fpm issues and sure enough, when I try rcctl start php72_fpm I get > php72_fpm(failed) In line with other OpenBSD configuration so far, I'd expect to be able to investigate some logs and read some man pages, but not sure where to find the error message in this case.