Source maps broken / don't load in firefox

[Graham42]

Node version: 0.10.36
Firefox version: 38.0.5

Steps to reproduce

1. Clone source and do npm install
2. Do npm run test
3. Do python3 -m http.server
4. Open Firefox and open the dev console (Debugger tab)
5. Got to http://0.0.0.0:8000/test/sourcemap_tester.html

In the inspector should see:

Error loading source:
loadSourceError

Edit: this seems to happen with sourceMapStyle embed or inline but not link

[Graham42]

Update: this bug appears to fixed in the dev build of Firefox. So maybe it's probably a bug in Firefox opposed to a bug in how we generate sourcemaps.

So in ~12 weeks should see this fix in release version of Firefox