How to override the location of .ivy2 directory when using sbt?

I'm using the x开发者_StackOverflowsbt 0.6.10 launcher. I would like the ivy files and jar files to be downloaded under a different directory. What is the best way to do this?

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With sbt 0.6.12, this can be done by overriding ivyCacheDirectory:

override def ivyCacheDirectory = Some(path("../ivycache")) 

See 0.6.11 announcement and IvyInterface for references.