I've recently switched from Grunt to Gulp task runner.
Is it possible to output as comment the line number in the compiled CSS files that would indicate where a given rule came from in the SASS file?
Such feature was enabled by default when I was using grunt-contrib-compass module.
Now I'm using gulp-sass for compiling my sass files.
Yes it is possible you need to pass it the right options:
.pipe(sass({
sourceComments: 'map',
sourceMap: 'sass',
outputStyle: 'nested'
}))