How to build gwt 2.4 now -- if errors in build

Okay, so the goal is to build Google Web Toolkit of version 2.4 now - when 2.5 is a  current stable. Issues seems to be fairly easy, but unfortunately -- fails from the first approach. Continuing tradition of writing memos for future, here it goes:

1. http://google-web-toolkit.googlecode.com/svn/releases/2.4/ - Main GWT source, release 2.4, checkout with subersion.
2. http://google-web-toolkit.googlecode.com/svn/tools/ - GWT-tools, some binary dependencies required for building.
   Trick is that they are versioned in a streamlined manner, and no-one leaves a note about which version of the tools does particular version of GWT require to build.
   So - to note, for GWT release 2.4 Tools rev 10417 are required. Do update Tools repo to this revision. 
3. Next step is straightforward - just set GWT_TOOLS environment variable to point to the tools working copy contianing rev 10417, descend into the GWT 2.4 release working copy, and issue ant.
   
   It did not work for me
   [gwt.javac] /home/lexaux/work/gwt/2_4/user/src/com/google/web/bindery/requestfactory/shared/impl/FindRequest.java:34: error: name clash: find(EntityProxyId) in FindRequest and find(EntityProxyId) in RequestContext have the same erasure, yet neither overrides the other
   [gwt.javac]   Request find(EntityProxyId proxy);
   
   Which is fairly weird, I thought, as ant explicitly sets language and class output level.
   After about a day of search, I just tried to downgrade my JDK to version 6 -- and voila; it worked. Looks like there is a change in generic treatment which stopped compilation.
   

After successful build, you can obtain results in build/lib - here's gwt-dev.jar and gwt-user.jar