aesthetics error if only argument is an expression

[emrichter]

I'm trying to dynamically generate a ggplot-object from within a function. For this, I save a parameter name like "color" or "fill" (dependent on the geom) as an expression and I unquote it within aes().
As long as I leave the x and y in the geom-function everything works. If I move them to ggplot() though, I get an error.
What am I missing?

Here a repex:

library(ggplot2)
library(rlang)

arg <- expr(color)

#working
ggplot(data = mpg) +
  geom_point(aes(displ, cty, !!arg := manufacturer))

#not working
ggplot(data = mpg, aes(displ, cty)) +
  geom_point(aes(!!arg := manufacturer))

[clauswilke]

I believe this is the same issue as #2675.

[emrichter]

Thanks a lot. So I'll wait till it's solved : )

[batpigandme]

@emrichter yes. I'll close this, since it's the same issue, though.

[hadley]

BTW there's an easy work around in the mean time:

ggplot(data = mpg, aes(displ, cty)) +
  geom_point(aes(,, !!arg := manufacturer))

[lock]

This old issue has been automatically locked. If you believe you have found a related problem, please file a new issue (with reprex) and link to this issue. https://reprex.tidyverse.org/