Concurrent builds under hudson

Here is a post from email thread about problems doing concurrent builds in hudson:

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You may want to consider moving the build directory from
$HOME/.grails/... to something in the source tree. Then when Hudson
removes the workspace, the build tree goes with it. Simply pass in the
system property "grails.work.dir" with the path of the workspace.

extracted from http://www.nabble.com/Re%3A-Build-automation-problems-with-Hudon-and-1.0.3.---FIXED-to17818458.html#a17819003