One Binary

I once worked on a team where every property change had to be checked in for a full build cycle, so the testers were left waiting whenever they needed a minor adjustment (did I mention that the build took too long as well?). I also worked on a team where the system administrators insisted on rebuilding from scratch for production (using the same scripts that we did), which meant that we had no proof that the version in production was the one that had been through testing. And so on.

If your team either has a code-mangling build or stores all the target settings with the code, that suggests that no one has thought through the design carefully enough to separate those features which are core to the application and those which are platform-specific. Or it could be worse: The team knows what to do but can’t prioritize the effort to make the change.

And one more thing: Keep the environment information versioned too. There’s nothing worse than breaking an environment configuration and not being able to figure out what changed. The environmental information should be versioned separately from the code, since they’ll change at different rates and for different reasons. Some teams use distributed version control systems for this (such as bazaar and git), since they make it easier to push changes made in production environments — as inevitably happens — back to the repository.