Debugging is made complicated by warning/messages only displayed once per session

[bguiastr]

Hi,

I am the maintainer of a package which is heavily depending on ggplot2. However, I just had the most difficult time fixing the warning:

#> Warning: Using `size` aesthetic for lines was deprecated in ggplot2 3.4.0.
#> Please use `linewidth` instead.

The reason was that this message returned by deprecate_soft0() is only displayed once per session (or every 8 hours) which made it very difficult for me to pinpoint the source of the issue (i.e. I had to keep restarting R to find and reproduce the issue).

While I clearly see the reasoning for messages/warning to the users, in my opinion it would make sense to have something like options(tidyverse.debug = TRUE) which would keep the messages/warnings turned on for developpers.

Please note that this issue is also applicable to other tidyverse packages such as dplyr, rlang::warn(), etc.

[yutannihilation]

Hi, ggplot2 uses lifecycle package to manage these warnings and messages. You can control lifecycle_verbosity.

cf., https://lifecycle.r-lib.org/reference/verbosity.html

library(ggplot2)

l <- geom_line(size = 10)
#> Warning: Using `size` aesthetic for lines was deprecated in ggplot2 3.4.0.
#> ℹ Please use `linewidth` instead.

# no warning for the second time
l <- geom_line(size = 10)

# you can see the warning again
options(lifecycle_verbosity = "warning")
l <- geom_line(size = 10)
#> Warning: Using `size` aesthetic for lines was deprecated in ggplot2 3.4.0.
#> ℹ Please use `linewidth` instead.

^{Created on 2023-02-25 with reprex v2.0.2}

[bguiastr]

@yutannihilation thanks a lot this is super useful, I would then suggest referencing this in the ggplot2 in packages vignette.

[yutannihilation]

Hmm, I have no idea how it should be documented. As it's a topic not specific to ggplot2, I'm not sure if ggplot2's vignette is the right place.

[teunbrand]

I agree. If the suggestion here is to omit lifecycle warnings more often, or add instructions about the verbosity in the message, then perhaps it would be best to file an issue with the lifecycle package. I'll close this issue here because it appears more closely related to the lifecycle messages.