GWT 2.6 - Java 6 conflict

Question

I'm trying to migrate to gwt 2.6 in a project compiled using java 6
The project is made of a library based on gwt and a gwt application.
When launching my app I get a "javascriptObject major.minor 51.0 exception"
I know that it's because of gwt 2.6 built in java 7
So I added <sourceLevel>1.6</sourceLevel> to my maven gwt plugin
But nothing changed, because I suppose that still persists the problem in the library side.
(Library compiled in java 6 with a GWT dependency in java7)
Have you got any Idea on how to inidicate sourceLevel while building my lib?
Thanks

Answer 1

GWT 2.6 “GA” will be compiled using Java 6 to overcome this bug. GWT 2.6 is supposed to still be compatible with Java 6; GWT 3.0 probably won't, at least for client-side code.

In the mean time, either move to Java 7 or wait for the next 2.6 release which is compatible with Java 6.

Note that the current GWT 2.6 RCs only require Java 7 at dev- and compile-time (for the GWT Compiler, DevMode and GWTTestCase); you can deploy your server-side code into a Java 6 VM.