[BUGFIX lts] Cleans up the DebugRenderTree more thoroughly on errors

packages/@ember/-internals/glimmer/lib/utils/debug-render-tree.ts

@@ -128,6 +128,15 @@ export default class DebugRenderTree<Bucket extends object = object> {
 
       // TODO: We could warn here? But this happens all the time in our tests?
 
+      // Clean up the root reference to prevent errors from happening if we
+      // attempt to capture the render tree (Ember Inspector may do this)
+      let root = expect(this.stack.toArray()[0], 'expected root state when resetting render tree');
+      let ref = this.refs.get(root);
+
+      if (ref !== undefined) {
+        this.roots.delete(ref);
+      }
+
       while (!this.stack.isEmpty()) {
         this.stack.pop();
       }

packages/@ember/-internals/glimmer/tests/integration/application/debug-render-tree-test.ts

@@ -1644,6 +1644,28 @@ if (ENV._DEBUG_RENDER_TREE) {
           this.assert.strictEqual(actual, expected, `Matching ${path}`);
         }
       }
+
+      async '@test cleans up correctly after errors'(assert: Assert) {
+        this.addTemplate(
+          'application',
+          strip`
+            <HelloWorld @name="first" />
+          `
+        );
+
+        this.addComponent('hello-world', {
+          ComponentClass: Component.extend({
+            init() {
+              throw new Error('oops!');
+            },
+          }),
+          template: 'Hello World',
+        });
+
+        await assert.rejectsAssertion(this.visit('/'), /oops!/);
+
+        assert.deepEqual(captureRenderTree(this.owner), [], 'there was no output');
+      }
     }
   );
 }