Don't know how to automatically pick scale for object of type NULL

[hadley]

cutpointr, drugCombo, ggeffects, HMP16SData, jtools, mousetrap, OutbreakTools, stormwindmodel, useful

library(ggplot2)

ggplot(mtcars, aes(mpg, wt)) + 
  geom_point(aes(shape = NULL))
#> Don't know how to automatically pick scale for object of type NULL. Defaulting to continuous.
#> Error: A continuous variable can not be mapped to shape

[hadley]

robustbase might also be related