“Locking assertion failure”... WTF?

I tried to build GWT today on a Ubuntu system. Compilation was failing during benchmarkviewer and was complaining about a “Locking assertion failure”. Well, come to find it, this of course has nothing to do with GWT. There is some sort of problem with how the JRE was built. Anyway... way to many rabbit holes later, I got on the right track and and found the fix.

sudo sed -i 's/XINERAMA/FAKEEXTN/g' /usr/lib/jvm/java-1.5.0-sun-1.5.0.15/jre/lib/i386/xawt/libmawt.so