warning message: The `size` argument of `element_line()` is deprecated as of ggplot2 3.4.0. about cowplot

[clauswilke]

Thanks for bringing this up. This is caused by a change in the latest released ggplot2. A couple of things to consider for a fix:

• The moment this is fixed, cowplot stops working with older versions of ggplot2. So this dependency needs to be recorded in the DESCRIPTION file.
• We should make sure we find all occurrences in the code that can cause this problem, so we need to fix only once.

Also, a general comment: When reporting issues, it's most productive to try to come up with a minimal example that causes the problem. Minimal examples should definitely not depend on other packages or have all sorts of irrelevant, distracting code. Here, I believe the problem is caused by using certain cowplot themes, but I can't tell from the provided example.

[clauswilke]

I see you provided a minimal example here: #189 (comment)

[Yunuuuu]

Oh, I'll put it here

[Yunuuuu]

A minimal example

library(ggplot2)
library(cowplot)


ggplot(mtcars) +
    geom_point(aes(mpg, drat)) +
    theme_cowplot()

Warning messages:
1: The `size` argument of `element_line()` is
deprecated as of ggplot2 3.4.0.
ℹ Please use the `linewidth` argument instead.
ℹ The deprecated feature was likely used in the
  cowplot package.
  Please report the issue at
  <https://github.com/wilkelab/cowplot/issues>.
This warning is displayed once every 8 hours.
Call `lifecycle::last_lifecycle_warnings()` to
see where this warning was generated. 
2: The `size` argument of `element_rect()` is
deprecated as of ggplot2 3.4.0.
ℹ Please use the `linewidth` argument instead.
ℹ The deprecated feature was likely used in the
  cowplot package.
  Please report the issue at
  <https://github.com/wilkelab/cowplot/issues>.
This warning is displayed once every 8 hours.
Call `lifecycle::last_lifecycle_warnings()` to
see where this warning was generated. 

[Yunuuuu]

fixed by #189