I require a catch-all virtual host, so I was using pick_first_virthost_on_nomatch and putting it first in the list of servers in my yaws.conf.
Everything worked fine until I added a new virtual host and called --hup on the server to load it. Then all those domains that went to my catch-all server started going to this new server even though it was not first in the config.

Is there a better way to do a catch-all virtual server?