# Build the catalog
	#
	# This method should be called at nitweb startup.
	fun build_catalog(modelbuilder: ModelBuilder, filter: nullable ModelFilter): Catalog do
		var catalog = new Catalog(modelbuilder)
		var mpackages = modelbuilder.model.collect_mpackages(filter)
		# Compute the poset
		for p in mpackages do
			var g = p.root
			assert g != null
			modelbuilder.scan_group(g)
		end
		# Build the catalog
		for mpackage in mpackages do
			catalog.package_page(mpackage)
			catalog.git_info(mpackage)
			catalog.mpackage_stats(mpackage)
		end
		return catalog
	end