Pass through original mergeDeep error in cause property

addon/utils/merge-deep.js

@@ -195,6 +195,7 @@ export default function mergeDeep(target, source, options = {}) {
       // this is very unlikely to be hit but lets throw an error otherwise
       throw new Error(
         'Unable to `mergeDeep` with your data. Are you trying to merge two ember-data objects? Please file an issue with ember-changeset.',
+        { cause: e },
       );
     }
   }