carto fails on numeric multiplication in styles

carto style bug

working carto
---------------

#land {
  polygon-fill:#0A202A;
  line-width:1.2;
}


non-working carto
------------------

#land {
  polygon-fill:#0A202A;
  line-width:1.2 * 2;    #<-- note multiplication
}

and (possibly as a result of the above)

@line_width_multiple:2;

#land {
  polygon-fill:#0A202A;
  line-width:1.2 * @line_width_multiple;
}