[caoilte]

We use Ruby extensively in testing and infrastructure and have lost months of cumulative developer time to this attitude. It works for a single user constantly making changes to a small piece of code and prepared to work out the solution to dependency change problems as soon as they come up. However, it doesn't scale to a team of people working on very large code bases.

One example of this is having a repeatable developer setup guide. If the dependencies might have changed by the time a new joiner starts your setup guide could very easily end up useless or misleading and that's without anything at all in your own codebase having changed.

Shrinkwrap fixes this, but always gets added after things went wrong several times already. It should be the default.