There are a lot of wrong ways to do this repair, believe me, I've tried. You stick "goof plugs" in, you can glop a bunch of silicone glue on the hole, you can try to wrap it up with electrical tape. None of these things work. Ask me how I know!
The correct way to fix this, and fix it right, is to replace a section of the trunkline. And the most important part is to get these cool 1/2 inch fittings. I've tried the simple "under pressure" fittings and they fail right away. These fittings, which I bought for a whopping $1.38 at Home Depot this morning, not only attach firmly, they have a screw top that cinches them down tight. It is ridiculously strong, which is what I want. This is a messy, muddy job, and I only want to have to do it once!