"end" event

I'm trying to write a gulp task that incorporates gulp-compass as follows:

```
.pipe(plugins.compass({
config_file: path.join(options.compass_config_dir, 'config.rb'),
sass: options.sass_dir,
css: options.css_dir,
image: options.output_dir,
import_path: options.output_dir,
require: ['susy'],
sourcemap: true
}))
.on('end', done);
```

The `done` callback is the callback for the gulp task itself. I'm calling the callback this way because earlier in the task, I make a `fs.access` call and call the `done` callback directly if I don't find a directory.

Unfortunately, the `end` event doesn't seem to be emitted. Is this intended?

Start by reproducing the shown gulp-compass pipeline and inspect how its stream signals completion. Confirm whether the “end” event is emitted and document the expected completion behavior for the gulp task callback.

Written by the indexing model from the issue text.