Gulp 4 sass forget to signal async completion
<p>I am trying to build my sass with gulp sass and i get the error:</p>

<p><strong>The following tasks did not complete: build, gulpSass
Did you forget to signal async completion?</strong></p>

<pre><code>function sass() {
  return gulp.src(paths.sass)
    .pipe(sourcemaps.init())
    .pipe(sass.sync().on('error', sass.logError))
    .pipe(sourcemaps.write())
    .pipe(gulp.dest(buildDir));
}

gulp.task('build', gulp.series(
  clean,
  sass,
  html,
  images
));
</code></pre>

<p>What is the problem?</p>