Unable to debug code debugger is shown in scss file instead of js

**I'm submitting a bug report**

* **Library Version:**
aurelia-cli 0.35.1

**Please tell us about your environment:**
* **Operating System:**
OSX 10.13.2
* **Node Version:**
8.9.0

* **NPM Version:**
6.7.0

* **Aurelia CLI OR JSPM OR Webpack AND Version**
aurelia CLi 0.35.1

* **Browser:**
Chrome 71.0

* **Language:**
ESNext

**Current behavior:**
Unable to debug code debugger is shown in scss file instead of js

**Expected/desired behavior:**
Should show debugger in corresponding JS file

* **What is the motivation / use case for changing the behavior?**
Not Sure

Start by reproducing the report with aurelia-cli 0.35.1, ESNext, and Chrome 71 on macOS, then inspect the generated JavaScript and SCSS debugger mappings. The issue names no source file or test; done means the Chrome debugger opens the corresponding JavaScript file rather than the SCSS file.

Written by the indexing model from the issue text.