rpmbuild question - follow on to gcc issues

[Steve]

I downloaded a src rpm, built it using rpmbuild and the spec file and ran it. So far, so good. Now I want to modify the source to add some debugging statements. The problem is that the src rpm contains a number of patches and one of the patches is to the file I want to modify. Now when I rpmbuild, the patching fails because the source file it is trying to patch doesn't look the same.

What is the Fedora way of dealing with this situation?

Let me know if this needs to be moved to the devel list.

Thanks,
Steve.