It looks like your pre-processor might be doing the division of lost-column: 1/2 and is making it lost-column: 0.5. Thus, lost-cycle doesn't have a denominator to reference. I've heard there might be some issues with Less regarding this.
As noted in issue #229 there can be an issue where Less does the
division of lost-column: 1/2 into lost-column: 0.5 which causes
problems especially with cycle. This adds a note to escape the division
with a ~”1/2”.