Package: x11proto-dev Version: 2018.4-4 Severity: wishlist It'd be good if x11proto-dev included the core protocol spec x11protocol.txt alongside the various extension .txt specs. It isn't hiding elsewhere is it?, in which case a cross-ref. x11proto-dev says Provides x11proto-core-dev where x11protocol.txt last lived, which had me thinking to find it there.