When you try to activate the web proxy on the Nightly from 8/13 you get the following error.
Couldn't open /etc/squid/squidGuard.conf - No such file or directory at /opt/vyatta/share/perl5/Vyatta/Webproxy.pm line 409.
From what it looks like the path for squidguard.conf has changed from /etc/squid/squidGuard.conf to /etc/squidguard/squidguard.conf. I was able to temporarily fix this with a simlink