function onFile( error, ns ) {
		if ( error ) {
			return clbk( error );
		}
		aliases = extractAliases( ns.toString() );
		findPkgs( opts, onGlob );
	}
Callback invoked after reading the `index.js` file of a namespace.

@private
@param {(Error|null)} error - error object
@param {(EmptyArray|StringArray)} ns - code with all package exports
@returns {void}