Getting this error:/home/gub/NewGub/gub/target/linux-64/src/lilypond-git.sv.gnu.org--lilypond.git-release-unstable/lily/include/ly-scm-list.hh:166:69: error: cannot call member function 'ly_scm_iterator_t<T, allow_mutation>::private_scm& ly_scm_iterator_t<T, allow_mutation>::dereference_scm() const [with T = const Book*; bool allow_mutation = true; ly_scm_iterator_t<T, allow_mutation>::private_scm = scm_unused_struct*]' without object
make[1]: *** [out/book.o] Error 1
-- Phil Holmes
