Compass sprites generate placeholders instead of classes (newer version doesn't require listfiles.rb)

_icons.scss

$disable-magic-sprite-selectors: true;
$icons-inline: true;
$icons-sprite-base-class: "%icons-sprite";
$icons-layout: smart;
$icons: sprite-map("icons/*.png");
@import "icons/*.png";

@each $img in sprite-names($icons) {
  %icon-#{$img} {
		@extend %icons-sprite;
		@include icons-sprite-dimensions($img);
		@include icons-sprite-position($img);
	}
}