replace @code{2.15.33-1} with the latest build):
@smallexample
-@uref{http://lilypond.org/download/binaries/test-output/lilypond-2.15.33-1.test-output.tar.bz2}
+@uref{http://lilypond.org/downloads/binaries/test-output/lilypond-2.15.33-1.test-output.tar.bz2}
@end smallexample
Copy the tarball into @file{gub/regtests/}, and tell the build