From Changelog at 16Jul: -files/blender-2.57-linux-3.patch This file is absent, and indeed, it is not used in new blender-2.63a-r2.ebuild. But there is another - blender-2.49b-r2.ebuild, and it uses this patch in src_prepare. So either remove blender-2.49, or return patches.
Adding Diego as primary maintainer because he was the one who added the patch
slyfox already fixed this one.