syntax error

I'm getting the following error while using source-map-support@0.4.0 with mocha-webpack:

```
node_modules/source-map-support/source-map-support.js:407
var hasStack = (arguments[1] && arguments[1].stack);
^
SyntaxError:

npm ERR! Darwin 12.6.0
npm ERR! argv "/usr/local/Cellar/node/5.3.0/bin/node" "/Users/dan/.node/bin/npm" "run" "test"
npm ERR! node v5.3.0
npm ERR! npm v3.8.3
npm ERR! code ELIFECYCLE
```

(The syntax error is blank as shown.)