Better error if rupture_mesh_spacing is missing
Better error if rupture_mesh_spacing is missing


Former-commit-id: 6034ec90f148a06787979d66f3163608753130fc [formerly 6034ec90f148a06787979d66f3163608753130fc [formerly bcea9ac329bbd3e2ec30e8466330c7542209fe63]]
Former-commit-id: c39a6feb091bbe9271b763b81da64b949e49262d
Former-commit-id: e47f0110f8bb74b17e9a51f4fe892daa4744aba7
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine