[drumdance]

Here's an example:

A few weeks ago we had an issue where a db migration would not work on some of our developer machines (it worked fine on mine and in staging and in production). After a lot of sleuthing, we found that it was because their version of the database was slightly different because they had installed it months after I did. Furthermore, it was a real pain to roll back to the appropriate version.

A container that locked down the db version would have avoided all that.

[maccard]

We just have the particular versions of tools we rely on checked into perforce, and when there's an upgrade, you don't have to do anything different and everyone gets the upgrade.