which rolls the tarball file(../releases/lilypond-0.1.73.tar.gz)
and leaves your patch as file(./lilypond-0.1.73.jcn1.diff).
footnote('Make diff' generates a patch between two tarballs. For
-more info type 'make diff help=='. We assume that there is a tarball
+more info type 'make diff help=='.) We assume that there is a tarball
file(lilypond-0.1.73.tar.gz) in the directory file(../releases).