Hi,
I wrote up a little tutorial on how get yourself setup to track down Eclipse GCJ problems:
http://wiki.eclipse.org/index.php/Debugging_Eclipse_GCJ_Problems
Please feel free to add to it and / or correct any errors that might be present. Also, if you have any questions, feel free to drop me a line.
Cheers, Ben
java-devel@lists.fedoraproject.org