A check ask's packages may need something only some build nodes have (mesh-build-node's integration tests read the
Node build module's installed toolchain). An ask now names its Needs; a holder lacking one ends the ask's step refused
as declined and drops the message for its asker to put again, skipping that worker until its next pull wait; a level's
packages whose declared needs the node lacks are left untested and named unmet, for the asker to place.