fixup: Ensure node stop is attempted on start failure

tests/fixture/e2e/helpers.go

@@ -206,17 +206,18 @@ func CheckBootstrapIsPossible(network testnet.Network) {
 	}
 	ginkgo.By("checking if bootstrap is possible with the current network state")
 
-	// Call network.AddEphemeralNode instead of AddEphemeralNode for compatibility
+	// Call network.AddEphemeralNode instead of AddEphemeralNode to support
+	// checking for bootstrap implicitly on teardown via a function registered
 	// with ginkgo.DeferCleanup. It's not possible to call DeferCleanup from
 	// within a function called by DeferCleanup.
 	node, err := network.AddEphemeralNode(ginkgo.GinkgoWriter, testnet.FlagsMap{})
+	require.NoError(err)
+
 	defer func() {
-		if node != nil {
-			tests.Outf("Shutting down ephemeral node %s\n", node.GetID())
-			require.NoError(node.Stop())
-		}
+		tests.Outf("Shutting down ephemeral node %s\n", node.GetID())
+		require.NoError(node.Stop())
 	}()
-	require.NoError(err)
+
 	WaitForHealthy(node)
 }
 

tests/fixture/testnet/local/network.go

@@ -673,7 +673,19 @@ func (ln *LocalNetwork) AddLocalNode(w io.Writer, node *LocalNode, isEphemeral b
 	if err := node.WriteConfig(); err != nil {
 		return nil, err
 	}
-	return node, node.Start(w, ln.ExecPath)
+
+	err = node.Start(w, ln.ExecPath)
+	if err != nil {
+		// Attempt to stop an unhealthy node to provide some assurance to the caller
+		// that an error condition will not result in a lingering process.
+		stopErr := node.Stop()
+		if stopErr != nil {
+			err = errors.Join(err, stopErr)
+		}
+		return nil, err
+	}
+
+	return node, nil
 }
 
 func (ln *LocalNetwork) GetBootstrapIPsAndIDs() ([]string, []string, error) {