Error message not that helpful in `labs()` if set to `element_blank()`

[olivroy]

I used to do this to remove axis labels

ggplot(mtcars, aes(cyl, mpg)) + geom_point() + labs(x = element_blank())

With the new ggplot2, I get the new warning.

#> `label` cannot be a <ggplot2::element_blank> object. 

The warning isn't that helpful. Took me a while to figure it out in a big plot construction.

Turns out I just have to use labs(x = NULL) instead.

I will change that everywhere in my code. But the problem comes when I use ggplotly().

ggplotly(ggplot(mtcars, aes(cyl, mpg)) + geom_point() + labs(x = element_blank()))
#> Erreur in as.vector(x, "character") : 
#>  cannot coerce type 'object' to vector of type 'character'

I wonder if that's an issue that should be fixed in ggplot2 (better warning), plotly (work with this), or my code. Possibly all 3, but I guess we can wait for more reports before taking action. I will update my code to get rid of element_blank() in the labs() calls.

Research notes
Changes occured in #6364

https://github.com/tidyverse/ggplot2/blame/961b194941380faa77addafd9d9f46b2d105ba8e/tests/testthat/_snaps/theme.md#L124