geom_rrect does not work with factors

[pteridin]

geom_rrect seems to get wrong informations about the heights/widths of the rounded rectangles when used on factors. Thus no rounded rectangle is shown, but some triangle like shape.

Minimal working example:

tibble(Field = c("A","B","C")) %>%  
   ggplot() + 
   ggchicklet:::geom_rrect(aes(fill = Field, ymin = Field, ymax=Field), xmin=0, xmax=1)