Such appeal shall be tried by the court in a summary way, without pleadings in writing and without a jury, after ten days’ notice to the adverse party, and the hearing shall be de novo. The amount finally assessed against or apportioned to each landowner, or fixed by agreement with him, as hereinbefore provided, shall be a lien enforceable in equity on his abutting land, from the time when the work of improvement has been completed, subject to his right of appeal and objections as aforesaid. Such lien shall be enforceable against any person deemed to have had notice of the proposed assessment under § 15.2-2412, but if no abstract of the resolution or ordinance authorizing the improvement is docketed as provided in § 15.2-2412, such lien shall be void as to all purchasers for valuable consideration without notice and lien creditors until and except from the time it is duly admitted to record in the county or city wherein the land is situated.