I'm not using his PPA, but the reason you're getting those errors is because his PPA only has builds for saucy and trusty, and you're using raring.

Easiest thing to do would be to ask him to add a build target for raring.

> Easiest thing to do would be to ask him to add a build target for raring.

Many PPA developers have a policy of only supporting Ubuntu releases that Canonical also supports.

Official support for raring expired 3 months ago. AFAIK it didn't even get the Heartbleed patch. The correct thing to do would be to update to trusty. It might even turn out to be the easiest thing as well, because you'll run more and more into these kinds of issues as everyone else leaves raring behind.