title: Gulp-compiled CSS folder missing from the Azure DevOps pipeline Build Artifact
body: <h2>A little background...</h2>
  
  <p>I have a small dotnet core application that is hosted on Azure and is being built and deployed using Azure DevOps Pipelines. Before we started using the DevOps Pipelines the CI was hooked up directly to Azure which compiled fine but took an actual lifetime to deploy, hence the decision to move.</p>
  
  <p><strong>However, the build pipeline no longer compiles or outputs the sass/css folder</strong></p>
  
  <p>Everything else works okay - I check in, the Build pipeline picks up my commits and has the following steps:</p>
  
  <ol>
  <li>Restore [.NET Core]</li>
  <li>Build [.NET Core]</li>
  <li>Publish [.NET Core]</li>
  <li>Publish Build Artifact</li>
  </ol>
  
  <p>Part of step 3 (Publish) uses a Gulp task:</p>
  
  <pre><code>gulp.task('prod', function (callback) {
      runSequence('clean','set-prod',
      ['icon-sprite', 'logo-sprite', 'images', 'sass', 'modernizr', 'mainjs', 'adminjs'], 
             callback);
  });
  </code></pre>
  
  <p>And locally (and previously) this generated five folders:</p>
  
  <blockquote>
    <ul>
    <li>icons  </li>
    <li>img  </li>
    <li>js  </li>
    <li>logos  </li>
    <li>css (now mysteriously missing in action)  </li>
    </ul>
  </blockquote>
  
  <h2>Variations I've tried</h2>
  
  <p>I've tried deleting my local css folder and running the CLI <code>dotnet publish</code> <em>exactly the same way</em> the Pipeline does and that appears to work fine locally.</p>
  
  <p>I've also stripped the sass task way back in case that was causing an issue somewhere in the pipeline, so that now looks like this:</p>
  
  <pre><code>return gulp.src('src/sass/style.scss')
      .pipe(sass({outputStyle: 'compressed'}))
      .pipe(gulp.dest('wwwroot/dist/css));
  </code></pre>
  
  <p>I can see all of the output in the console logs on the Pipeline and it successfully executes the sass task:</p>
  
  <pre><code>2019-01-02T14:43:51.3558593Z   [14:43:51] Starting 'sass'...
  2019-01-02T14:43:51.9284145Z   [14:43:51] Finished 'sass' after 524 ms
  </code></pre>
  
  <p>There are no other errors or warnings in the build script and everything completes and fires off the Release pipeline (which copies the artifact up to the Azure site).</p>
  
  <h2>Speculation</h2>
  
  <p>I would expect an error somewhere... but nothing - all of the green ticks are downright cheerful... so I'm a little stumped at what may or may not be happening! I can only think that there must be some dependency or something missing in the Pipeline environment? Orrrrr maybe I'm missing a Pipeline step?</p>
  
  <p>Any help or nudges or ideas would be greatly appreciated! Thank you for sticking it out through my small essay and for any help you can provide :)</p>