Source Map install attempt

I’ve attempted to get my source maps running with Chrome (latest version on Mac OS 10.8.5) with this grunt config, locally using MAMP:

less: {
  dist: {
    files: {
      'assets/css/main.min.css': [
    options: {
      compress: true,
      // LESS source map
      // To enable, set sourceMap to true and update sourceMapRootpath based on your install
      sourceMap: true,
      sourceMapFilename: 'assets/css/',
      sourceMapRootpath: '/wp-content/themes/roots-master/'

When this is saved, this is returned:

>> File "Gruntfile.js" changed.

Running "jshint:all" (jshint) task
>> 2 files lint free.

Running "uglify:dist" (uglify) task
File "assets/js/scripts.min.js" created.

Running "version" task
Versioning assets/css/main.min.css...OK
Versioning assets/js/scripts.min.js...OK
"lib/scripts.php" updated with new CSS/JS versions.

Done, without errors.
Completed in 1.016s at Sat Nov 30 2013 21:25:26 GMT-1000 (HST) - Waiting...
>> File "assets/js/scripts.min.js" changed.

I was told this could not be debugged until the .map file is created.

I’m wondering if my case is “special” because of a kink when installing Roots. I went ahead and ran the npm install before I properly installed Wordpress. Realizing my oversight, I trashed the roots folder and finished my local install of WP.

I then restarted and npm installed, and everything was working perfectly - until this. I looked on grunt.jss and less.js on github and found only one article.

This looks promising, but Grunt is not mentioned.

$ lessc --version

this is returned:

-bash: lessc: command not found

Would installing LESS over it screw me over royally?

Npm does not reference Less that way, at least not any longer. try less --version