roachtest: allow saving clusters more generally

Even if neither --debug nor --debug-always are specified.

Author: tbg

pkg/cmd/roachtest/cluster.go

@@ -1109,6 +1109,12 @@ func (c *clusterImpl) Save(ctx context.Context, msg string, l *logger.Logger) {
 	c.destroyState.mu.Unlock()
 }
 
+func (c *clusterImpl) saved() bool {
+	c.destroyState.mu.Lock()
+	defer c.destroyState.mu.Unlock()
+	return c.destroyState.mu.saved
+}
+
 var errClusterNotFound = errors.New("cluster not found")
 
 // validateCluster takes a cluster and checks that the reality corresponds to

pkg/cmd/roachtest/test_runner.go

@@ -987,10 +987,12 @@ func (r *testRunner) runWorker(
 					// Continue with a fresh cluster.
 					c = nil
 				case NoDebug:
-					// On any test failure or error, we destroy the cluster. We could be
-					// more selective, but this sounds safer.
-					l.PrintfCtx(ctx, "destroying cluster %s because: %s", c, failureMsg)
-					c.Destroy(context.Background(), closeLogger, l)
+					if !c.saved() {
+						// On any test failure or error, we destroy the cluster. We could be
+						// more selective, but this sounds safer.
+						l.PrintfCtx(ctx, "destroying cluster %s because: %s", c, failureMsg)
+						c.Destroy(context.Background(), closeLogger, l)
+					}
 					c = nil
 				}
 			}