I've just committed some changes to
JFace that rely on the new typed listeners added to SWT
(see https://bugs.eclipse.org/bugs/show_bug.cgi?id=81334).
So...if you load the latest JFace from
HEAD, you'll also need to load SWT from head.
If you don't normally keep SWT checked
out in your workspace, please see
http://www.eclipse.org/swt/cvs.php
for special instructions on updating
the classpath for SWT.