Gulp ruby-sass and autoprefixer do not get along - sass

Question

I have a styles task in my gulpfile:
gulp.task('styles', function () {
var sass = require('gulp-ruby-sass');
var autoprefixer = require('gulp-autoprefixer');
return gulp.src('app/styles/main.scss')
.pipe(sass({sourcemap: true, sourcemapPath: '../scss'}))
.on('error', function (err) { console.log(err.message); })
.pipe(autoprefixer({
browsers: ['last 2 versions'],
cascade: false
}))
.pipe(gulp.dest('.tmp/styles'));
});
which generates this in the console:
[14:25:21] Starting 'styles'...
[14:25:21] gulp-ruby-sass: stderr: DEPRECATION WARNING: Passing --sourcemap without a value is deprecated.
Sourcemaps are now generated by default, so this flag has no effect.
[14:25:21] gulp-ruby-sass: directory
[14:25:25] gulp-ruby-sass: write main.css
write main.css.map
events.js:72
throw er; // Unhandled 'error' event
^
Error: /Users/stevelombardi/Documents/command-central/ccgulp/main.css.map:3:3: Unknown word
IF I comment out the pipe to autoprefixer, no errors, everything compiles. What's the deal here?
Note, I also cannot seem to disable the writing of a sourcemap. I tried all the other settings from the repo page for grunt-ruby-sass and none work.
I can live without autoprefixer, but would love to get it working...

Answer 1

The issue seems to happen related to the main.css.map, even if you didn't want one, using gulp-ruby-sass#0.7.1 at the time I am writing this.
I've come across two different solutions so far:
1) If you don't need sourcemaps:
gulp.task('styles', function() {
gulp.src('app/styles/main.scss')
.pipe(sass({
"sourcemap=none": true // hack to allow auto-prefixer to work
}))
.pipe(prefix("last 2 versions"))
.pipe(gulp.dest('css'));
});
This is what I have used as I recently encountered this issue.
2) If you do need sourcemaps:
Then you should try gulp-ruby-sass#1.0.0-alpha
(relevent github issue)

Answer 2

Instead of:
browsers: ['last 2 versions'],
Try this:
browsers: ['last 2 version'],
If that doesn't work, I've had better luck with gulp-sass and gulp-sourcemaps.
// Compile Sass & create sourcemap
.pipe(sourcemaps.init())
.pipe(sass())
.pipe(sourcemaps.write())
.pipe(gulp.dest('css'))
// Autoprefix, load existing sourcemap, create updated sourcemap
.pipe(sourcemaps.init({loadMaps: true}))
.pipe(autoprefixer('last 2 version')
.pipe(sourcemaps.write('./'))
.pipe(gulp.dest('css'))