When using xstream 1.4.3 on a Mac, it simply locks up a thread.
Note that this affects Macs ONLY. Code is fine on Windows and Linux.
Debugging shows that line 38 in class com.thoughtworks.xstream.core.JVM never exists from the 'loadClass("java.awt.Color")'
Attached is the stack trace.
Further investigation shows that this is a known problem on Macs and that loading class java.awt.Color has nasty side-effects which cause threads to lock up on some cases.
either load a different class, or find a different way to test whether AWT is present.