Koala does not compile scss file, where could be the error?

Question

Sass

// Sass project settings, you can edit it and set custom settings.
{
  // The mappings of source directory and output directory
  "mappings": [
     {	
      "src": "sass/style.scss",
     	"dest": "stylesheets/style.css"
     }
  ],

  // Add the ignore rules that Koala will not search them.
  // e.g. ["*.json", "*.txt", "test", "path/libs"]
  "ignores": ["*.css"],

  // Compile options of Sass.
  "options": {

    // Output style. Can be nested (default), compact, compressed, or expanded.
    "outputStyle": "nested",

    // Emit comments in the generated CSS indicating the corresponding source line.
    "lineComments": false,

    // Emit extra information in the generated CSS that can be used by the FireSass Firebug plugin.
    "debugInfo": false,

    // Create sourcemap files next to the generated CSS files
    "sourceMap": false,

    // Use Unix-style newlines in written files.
    "unixNewlines": false,

        // auto add vendor prefixes to rules
        "autoprefix": false
  },

  // Other compile options, use the full name of options.
  // e.g, ["--scss", ... ,"--no-cache"].
  // Run the command 'sass -h' to see more options.
  "customOptions": [],

  // An array of filesystem paths or importers which should be searched for Sass templates imported with the @import directive.
  "includePaths": ["--load-path sass/base.scss",
                        "--load-path sass/typography.scss",
                      "--load-path sass/grids.scss"],

  // A array of ruby libraries, require them before running Sass.
  "requireLibs": []
}

these are the settings from the project

Answer 1

You need to use Sass 3.3+ and install the Susy gem itself, maybe Koala won't catch it. For example, Prepros cannot be forced to use custom Sass (not the one in the box) and, accordingly, use third-party gems, maybe in Koala the same story.

Answer 2

A koala can never clearly write mistakes.
I advise you to abandon it and write tasks for gulp.

Answer 3

C:\Program Files (x86)\Koala\app\scripts\compilers file SassCompiler
exec(command, {timeout: 10000, maxBuffer: 2000*1024}, function (error, stdout, stderr) {
default timeout 5000