create_source_map option. This Grunt plugin will add that comment for you.
Just install via npm like usual:
npm install grunt-append-sourcemapping
To append a sourcemapping URL comment at the end of the minified file, you need to tell Grunt to load the new task and then add another section to your config:
grunt; // Load the taskgrunt;
This will append the following comment to the end of lib.min.js (see this jQuery bug ticket for full details on why the wrapping multiline comment is necessary - in short, it's a workaround for an Internet Explorer issue):
You can specify any number of files in the
files property, and as this is a Grunt multitask you can specify different targets too.