Incremental build with anytime rollback

Ok, I get the incremental build and I'm working on it already, but I don't got the idea how to do rollbacks in case I need to. At the moment I'm using MSBuild and CruiseControl.NET to create the build system; everything is going smooth right up to the point when I start thinking about rollbacks. How is it achiev开发者_C百科ed using either MSBuild or CruiseControl.NET?

Cheers!

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Check out the previous version of the code, then check it in as a new version. This won't require any change at all to your build system, as it won't see any difference between this and a normal code edit. This also keeps the "unwanted" code change in your source control history so you can retrieve it when you realise that rolling back was also a mistake.