From fbe22e53a9be74928f885ee58ee51e06cd38a33d Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Sat, 30 May 2015 22:02:56 -0400
Subject: [PATCH] add check for dynamic node and output error message
 accordingly

---
 src/babel/transformation/file/index.js | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/babel/transformation/file/index.js b/src/babel/transformation/file/index.js
index a16be564ee..7094b1eca2 100644
--- a/src/babel/transformation/file/index.js
+++ b/src/babel/transformation/file/index.js
@@ -385,9 +385,14 @@ export default class File {
   }
 
   errorWithNode(node, msg, Error = SyntaxError) {
-    var loc = node.loc.start;
-    var err = new Error(`Line ${loc.line}: ${msg}`);
-    err.loc = loc;
+    var err;
+    if (node.loc) {
+      var loc = node.loc.start;
+      err = new Error(`Line ${loc.line}: ${msg}`);
+      err.loc = loc;
+    } else {
+      err = new Error("There's been an error on a dynamic node. This is almost certainly an internal error. Please report it.");
+    }
     return err;
   }