Inevitably during your development process, the client is going to want to see how things are going. And typically in these cases you don't want to demo on the actual development environment. So you setup a test site to demo everything which may or may not contain all those lovely Drupal development modules (i.e. coder, devel, etc...). And if that's true, what if there are stray 'dsm' calls in your committed code? I mean it's safe to assume you grabbed a copy from your repo which is still under active development so it's safe to assume there's some dev code in there. And that code will cause critical errors with those dev modules missing. The last thing you want is to show big error pages during a demo!
Now I know this is a lot of if's but it could happen (trust me...). Here's how to avoid it:
What you'll need: Your fingers and cooperative developers

