The environment variable FORCE_DEPLOY_ROOT is used for debug Java plugin/Java webstart application, it will point to the local build output directory, such as C:\build\jdk7-partial\tmp\deploy\jre-image, after setup this environment globally, the Java control panel from Window control panel can't be start anymore, it reported error:

"A Java Exception has occured".

This limited our ability to debug Java control panel changes using partial build.