While it's not recommended that you develop 2MB JS files, it seems that it *does* happen, and it's about the time that your files get this large that a project (naturally!) turns to the Dojo compressor. Unfortunantly, the default set of arguments doesn't hold up to a file this big, and strange exceptions result. Here is a modified recipe for use with the kinds of files that really, *really* need the Dojo compressor:

java -Xmn100M -Xms500M -Xmx500M -jar custom_rhino.jar -opt -1 -c HUGE.js > smaller.js