Hi, ok, thanks, I'll try to fix this soon! (It's my first commit ever to someone else's project so sorry for any inconvenience!) 

> In php/commands/scaffold.php:
> 
> > @@ -146,6 +146,39 @@ function _s( $args, $assoc_args ) {
> >  
> >  	}
> >  
> > +	/**
> > +	 * Generate empty child theme (twentytwelve by default).
> > +	 *
> > +	 * @synopsis <slug> [--theme_name=<title>] [--parent_theme=<title>] [--author=<full-name>] [--author_uri=<http-url>] [--theme_uri=<http-url>] [--activate]
> > +	 */
> > +	function child_theme( $args, $assoc_args ) {
> > +
> > +		$theme_slug = $args[0];
> > +		$theme_path = WP_CONTENT_DIR . "/themes";
> > +
> > +		$data = wp_parse_args( $assoc_args, array(
> > +			'theme_name' => ucfirst( $theme_slug ),
> > +			'parent_theme' => 'twentytwelve',
> I'm not sure defaulting to Twentytwelve is a good idea. What if the user deleted it at some point? I think --parent_theme should be a mandatory parameter.
> 
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