LESS Sourcemap to parent directory

Keywords: css less web-compiler

Question: 

I have a styles.less file in the directory: /Content/custom/styles.less.
And then I have bootstrap.less in the directory /Content/custom/bootstrap.less.

styles.less imports bootstrap:

/* bootstrap */
@import "../bootstrap/bootstrap.less";
/* style overrides */
@import "somefile.less"

I am using WebCompiler to generate the css and also the less mappings:

{
  "compilers": {
    "less": {
      "autoPrefix": "",
      "cssComb": "none",
      "ieCompat": true,
      "strictMath": false,
      "strictUnits": false,
      "relativeUrls": true,
      "rootPath": "",
      "sourceMapRoot": "",
      "sourceMapBasePath": "",
      "sourceMap": true
    },

When I run the site, all the less mappings work fine except for the bootstrap mapping which comes out as: http://localhost:1234/content/custom/C:/_path_/Content/bootstrap/scaffolding.less

How do I get the map to be: http://localhost:1234/content/bootstrap/scaffolding.less ?

Answers: