title: Gulp Autoprefixer Not Working
body: <p>I'm unable to get Autoprefixer to work with Gulp. I'm using opacity in my CSS, gradients, and transforms and there aren't any vendor prefixes showing up. Otherwise, everything else is working.</p>
  
  <p>Here's my gulp file:</p>
  
  <pre><code>var gulp = require('gulp');
  
  var lr = require('tiny-lr');
  var jshint = require('gulp-jshint');
  var sass = require('gulp-sass');
  var autoprefixer = require('gulp-autoprefixer');
  var minifycss = require('gulp-minify-css');
  var concat = require('gulp-concat');
  var rename = require('gulp-rename');
  var livereload = require('gulp-livereload');
  var server = lr();
  var plumber = require('gulp-plumber');
  
  var onError = function (err) {  
    gutil.beep();
    console.log(err);
  };
  
  gulp.task('lint', function() {
      return gulp.src('js/all.js')
          .pipe(jshint())
          .pipe(jshint.reporter('default'));
  });
  
  gulp.task('sass', function() {
      return gulp.src('scss/*.scss')
          .pipe(sass({errLogToConsole: true}))
          .pipe(autoprefixer('last 2 versions', 'safari 5', 'ie6', 'ie7', 'ie 8', 'ie 9', 'opera 12.1', 'ios 6', 'android 4'))
          .pipe(minifycss())
          .pipe(gulp.dest(''))
          .pipe(plumber({
              errorHandler: onError
          }))
          .pipe(livereload(server));
  });
  
  
  gulp.task('scripts', function() {
      return gulp.src(['js/fittext.js', 'js/fitvids.js', 'js/snap-scroll.js', 'js/cycle-min.js', 'js/all.js', 'js/respond.js'])
          .pipe(concat('all.js'))
          .pipe(gulp.dest('js/min'))
          .pipe(rename('main.min.js'))
          .pipe(gulp.dest('js/min'))
          .pipe(plumber({
              errorHandler: onError
          }))
          .pipe(livereload(server));
  });
  
  gulp.task('watch', function() {
      livereload.listen();
      gulp.watch('**/*.php').on('change', livereload.changed);
      gulp.watch('js/*.js', ['scripts']);
      gulp.watch('scss/**/*.scss', ['sass']);  
  });
  
  gulp.task('default', ['lint', 'sass', 'scripts', 'watch']);
  </code></pre>
  
  <ul>
  <li>I've searched and tried various solutions to this problem without avail. I've also tried changing <code>.pipe(gulp.dest(''))</code> to a specific directory (like <a href="https://stackoverflow.com/questions/22506171/gulp-autoprefixer-not-compiling-css3#answer-22592576">this answer suggested</a>), without any luck.</li>
  </ul>
  
  <p>I appreciate any help you can offer.</p>
  
  <p><strong>* UPDATE *</strong></p>
  
  <p><em>I'd like to note my naivety on Autoprefixer adding a prefix for opacity, which it obviously does not.</em></p>