Make delivery asset outcomes disjoint

cmd/releasekit/main.go

@@ -230,6 +230,7 @@ func runDelivery(ctx context.Context, invocation cli.Invocation, stdout, stderr
 	if err != nil {
 		fmt.Fprintf(stderr, "delivery state=%s version=%s commit=%s url=%s: %v\n", result.State, result.Version, result.CandidateCommit, result.ReleaseURL, err)
 		writeDeliveryAssets(stderr, result)
+		writeDeliveryRecovery(stderr, result)
 		if errors.Is(err, releasekit.ErrInvalidVersion) {
 			return 2
 		}
@@ -257,6 +258,24 @@ func writeDeliveryAssets(output io.Writer, result releasekit.DeliveryResult) {
 	}
 }
 
+func writeDeliveryRecovery(output io.Writer, result releasekit.DeliveryResult) {
+	switch result.State {
+	case releasekit.DeliveryNotAttempted:
+		fmt.Fprintln(output, "recovery: fix the local or preflight failure before retrying; no remote write was attempted")
+	case releasekit.DeliveryPartial:
+		fmt.Fprintln(output, "recovery: fix the reported cause, then retry this version")
+	case releasekit.DeliveryConflict:
+		fmt.Fprintln(output, "recovery: investigate conflicting hosted content; use a new version if the source or published contents need correction")
+	case releasekit.DeliveryUnknown:
+		fmt.Fprintln(output, "recovery: resolve the remote state before retrying")
+	default:
+		return
+	}
+	if len(result.Matching)+len(result.Uploaded)+len(result.Conflicting)+len(result.Uncertain) != 0 {
+		fmt.Fprintln(output, "if rebuilding could change asset bytes already on the server, retain the original build artifacts and retry with deliver --assets DIR")
+	}
+}
+
 func buildResultFromReceipt(receipt cli.BuildReceipt) *releasekit.BuildResult {
 	result := &releasekit.BuildResult{
 		RepositoryDir: receipt.RepositoryDir, CandidateCommit: receipt.CandidateCommit, SourceVerified: receipt.SourceVerified,