Ignore JVM warnings

[Richard Schneeman]

I'm trying to compile some assets with sprockets (I'm the current maintainer) and i'm getting warnings about _JAVA_OPTIONS being picked up in my compiled output:

  1) Failure:
TestClosureCompressor#test_compress_javascript [test/test_closure_compressor.rb:15]:
--- expected
+++ actual
@@ -1,2 +1,3 @@
-"function foo(){return!0};
+"Picked up _JAVA_OPTIONS: -Xmx2048m -Xms512m
+function foo(){return!0};
 "

Have you seen this before? Any idea how to disable or seperate out that warning from the compiled output?