Conversion Failure Warnings

[BenjaminWolfe]

On Ubuntu 18.04 LTS, running R in VSCode, whether with PDF (apparently the default) or PNG (apparently the default for the VSCode session watcher), running this code—

library(dplyr)
library(ggplot2)
library(signs)

mtcars %>%
  group_by(cyl) %>%
  summarise(records = n(), .groups = "drop") %>%
  mutate(cyl = -cyl) %>%
  ggplot(aes(cyl, records)) + 
  geom_point() +
  scale_x_continuous(label = signs)

—works, but spawns 50 or more errors, all of which look like this with varying hex codes at the end and different numerical values:

1: In grid.Call(C_textBounds, as.graphicsAnnot(x$label),  ... :
  conversion failure on '−8.0' in 'mbcsToSbcs': dot substituted for <e2>

The warnings do not occur…

1. if I remove the mutate line (and so there are no negative numbers), or
2. if I run it on my Macbook.

I also had no trouble running it on Windows when I developed it, of course, and it has always passed CRAN checks! 🤷

[plbaldoni]

Any updates on this issue?

I am also getting similar warnings on my end (R version 4.0.3 (2020-10-10), Platform: x86_64-apple-darwin17.0 (64-bit), Running under: macOS Big Sur 10.16).

This is how an output in PDF format looks like: