roachtest: fix test cluster check in maybeSaveClusterDueToInvariantProblems

This check previously called c.Nodes, which constructs a node list
with the passed in options. With nothing passed, this constructs
an empty node list which caused this check to always return.

Author: DarrylWong

pkg/cmd/roachtest/test_runner.go

@@ -1814,7 +1814,7 @@ func gatherFatalNodeLogs(t *testImpl, testLogger *logger.Logger) (string, error)
 func (r *testRunner) maybeSaveClusterDueToInvariantProblems(
 	ctx context.Context, t *testImpl, c *clusterImpl,
 ) {
-	if len(c.Nodes()) == 0 {
+	if len(c.All()) == 0 {
 		return // test only
 	}
 	dets, err := c.RunWithDetails(ctx, t.L(), option.WithNodes(c.All()),

pkg/cmd/roachtest/tests/invariant_check_detection.go

@@ -30,7 +30,7 @@ func registerInvariantCheckDetection(r registry.Registry) {
 			Name:             fmt.Sprintf("invariant-check-detection/failed=%t", failed),
 			Owner:            registry.OwnerTestEng,
 			Suites:           registry.ManualOnly,
-			Cluster:          spec.ClusterSpec{NodeCount: 1, CPUs: 4, ReusePolicy: spec.ReusePolicyNone{}},
+			Cluster:          r.MakeClusterSpec(1, spec.CPU(4), spec.ReuseNone(), spec.VolumeSize(100), spec.GCEVolumeType("pd-ssd")),
 			Run: func(ctx context.Context, t test.Test, c cluster.Cluster) {
 				runInvariantCheckDetection(ctx, t, c, failed)
 			},