LineCap::Square produces same result as LineCap::Butt

[sbauer322]

I seem to be having trouble with LineCap::Square. In particular, it doesn't go past the point like LineCap::Round does. Instead it stops right at the point like LineCap::Butt, which is the default.

I've attached some sample images below with several individual lines. The black dots are the start and end points of these lines.

The helpful people of the nannou Slack suggested this might be a problem with lyon so I figure I should ask here first before reaching out to lyon.

EDIT: Here is the sketch I was working on when I noticed the problem, if it helps reproduce the issue. You'll need to comment / uncomment the two cap functions as appropriate.

LineCap::Butt

LineCap::Round

LineCap::Square