Error: File not found: addon.sass

I’m adding ember-freestyle to my project using instruction, but during building broccoli throws error related to addon.sass.. Without this package, the error doesn’t occur. I try to import styles in app.sass @import 'ember-freestyle' or add it to ember-cli-build like:

nodeAssets: {    
 "ember-freestyle": {
     srcDir: "addon/styles",
     import: ["addon.sass"]
  }
},

Error:

Project dependencies:

"dependencies": {
    "cirilla": "1.0.5",
    "ember-cli-babel": "6.8.2",
    "ember-cli-htmlbars": "2.0.3",
    "ember-cli-htmlbars-inline-precompile": "1.0.2",
    "ember-cli-sass": "7.0.0",
    "ember-power-select": "1.9.6"
  },
  "devDependencies": {
    "@ac/addon-code-quality": "0.1.1",
    "@ac/eslint-config": "0.2.3",
    "babel-plugin-preval": "1.5.0",
    "broccoli-asset-rev": "2.6.0",
    "cross-env": "5.0.5",
    "ember-ajax": "3.0.0",
    "ember-cli": "2.15.1",
    "ember-cli-babel": "6.8.2",
    "ember-cli-dependency-checker": "1.3.0",
    "ember-cli-eslint": "4.2.0",
    "ember-cli-inject-live-reload": "1.7.0",
    "ember-cli-moment-shim": "^3.5.0",
    "ember-cli-qunit": "4.0.1",
    "ember-cli-sass-lint": "1.0.5",
    "ember-cli-shims": "1.1.0",
    "ember-cli-sri": "2.1.1",
    "ember-cli-template-lint": "0.7.3",
    "ember-cli-uglify": "1.2.0",
    "ember-cp-validations": "3.4.1",
    "ember-disable-prototype-extensions": "1.1.2",
    "ember-export-application-global": "2.0.0",
    "ember-file-upload": "2.1.1",
    "ember-load-initializers": "1.0.0",
    "ember-moment": "7.4.1",
    "ember-native-dom-helpers": "0.5.4",
    "ember-radio-button": "1.1.1",
    "ember-resolver": "4.5.0",
    "ember-source": "2.14.1",
    "ember-truth-helpers": "1.3.0",
    "loader.js": "4.6.0",
    "sass-lint": "1.10.2"
  },

@ac is a namespace to our internal registry.

[PoslinskiNet]

@chrislopresto maybe we could move to .css approach to avoid cross-extension node-sass issues? Would you merge such a PR if anyone would prepare one of these?

[PoslinskiNet]

@Biszkopt91 I think it is connected with https://github.com/aexmachina/ember-cli-sass/issues/163 … ember-freestyle has addon.scss, but the project supports *.sass (based on ember-cli-sass setting)