Source maps not read correctly when source file path contains spaces

[tjwoon]

When my source code is in a path with spaces, e.g. "Source Code", this task fails with the following output:

Running "concat_sourcemap:scripts" (concat_sourcemap) task
[D] Task source: /.../node_modules/grunt-concat-sourcemap/tasks/concat_sourcemap.js
Warning: Unable to read "Source%20Code/app.litcoffee" file (Error code: ENOENT). Use --force to continue.

concat_sourcemap options:

{
    sourcesContent: true
}

[tjwoon]

The .map file contains this:

{
  "version": 3,
  "file": "app.js",
  "sourceRoot": "../../Source%20Code/",
  "sources": [
    "app.litcoffee"
  ],
  "names": [],
  "mappings": "..."
}