From 9e41ce1a3d78ed523c496a3ffbdc9e9311370230 Mon Sep 17 00:00:00 2001
From: Robert Wagner <rwwagner90@gmail.com>
Date: Thu, 31 May 2018 09:45:12 -0400
Subject: [PATCH] Fix rootElement.getAttribute error (#812)

Closes #775
---
 ember_debug/libs/glimmer-tree.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/ember_debug/libs/glimmer-tree.js b/ember_debug/libs/glimmer-tree.js
index 3fe94f450a..34b4cb8b16 100644
--- a/ember_debug/libs/glimmer-tree.js
+++ b/ember_debug/libs/glimmer-tree.js
@@ -141,7 +141,9 @@ export default class {
 
     // set root element's id
     let rootElement = this.elementForRoot();
-    outletTree.value.elementId = rootElement.getAttribute('id');
+    if (rootElement instanceof HTMLElement) {
+      outletTree.value.elementId = rootElement.getAttribute('id');
+    }
     outletTree.value.tagName = 'div';
 
     return outletTree;