The node-engine writes a refused key, with the build's own error, at the indexer's fingerprint in composed-<node> for a placed module whose newest build the builder holds failed; a build queued or running stays unpublished (U1). A failed build of a placed module's newest fingerprint also moves the pass (takeBuildDone), so the key is written when it lands (U8). Builds: design 47 fix-unpublished-placed-module U1, U8, ADR 0593 §6