title: How to fix: Angular / Ionic v4 "Can't find stylesheet to import" from library in monorepo project
body: <p>I have a monorepo project that includes a library, several projects, and the main project. My ionic project is in the <code>projects</code> folder. </p>
  
  <p>I cannot build my ionic project (<code>ionic build</code> or <code>ng build</code>) because it imports a module from the main project (<code>src/</code>) which imports a sass file from a third project in the <code>libs/</code> folder. </p>
  
  <p>When building with <code>ionic build</code>, I get the error:</p>
  
  <p>"Can't find stylesheet to import."</p>
  
  <p><code>@import 'libs/...';</code></p>
  
  <p>When I build with the ng-cli, I get errors for each of the references to sass files imported from <code>libs/...</code> seemingly everywhere in the project, even files/modules that aren't imported in this project. </p>
  
  <p>I don't have any issue building other projects that import from the folder. </p>
  
  <p>The <code>package.json</code> file inside of the ionic project folder includes this snippet: </p>
  
  <pre><code>"config": {
      "ionic_webpack": "./webpack.config.js",
      "ionic_sass": "./sass.config.js",
      "ionic_source_map_type": "source-map"
    },
  </code></pre>
  
  <p>My custom config is pasted below, I've tried variations of including <code>../../</code> or not and running <code>ionic build</code> from both the root directory and the project root: </p>
  
  <pre><code>const useDefaultConfig = require('@ionic/app-scripts/config/sass.config.js');
  
  useDefaultConfig.includePaths.push('libs/path/to/assets/scss');
  useDefaultConfig.includePaths.push('libs/path/to/assets/scss/partials');
  useDefaultConfig.includePaths.push('../../libs/path/to/assets/scss');
  useDefaultConfig.includePaths.push('../../libs/path/to/assets/scss/partials');
  
  useDefaultConfig.includePaths.push('dist/path/to/assets/scss');
  useDefaultConfig.includePaths.push('dist/path/to/assets/scss/partials');
  useDefaultConfig.includePaths.push('../../dist/path/to/assets/scss');
  useDefaultConfig.includePaths.push('../../dist/path/to/assets/scss/partials');
  
  module.exports = useDefaultConfig;
  </code></pre>
  
  <p>I also tried doing </p>
  
  <pre><code>module.exports = function(){ return useDefualtConfig; };
  </code></pre>
  
  <p>I added paths to the <code>stylePreprocessorOptions.includePaths</code> in the project's section of the <code>angular.json</code> file like so: </p>
  
  <pre><code>"stylePreprocessorOptions": {
      "includePaths": [
          "libs/path",
          "libs/path/assets/scss",
          "libs/path/assets/scss/partials",
          "dist/path",
          "dist/path/assets/scss",
          "dist/path/assets/scss/partials"
      ]
  },
  </code></pre>
  
  <p>I also included the paths in both <code>tsconfig.app.json</code> and <code>tsconfig.json</code>.</p>