Thanks, Mara for your prompt answer.
Yes, I think in the example I gave, the issue is that the latter shall not be a data frame. If I sum over one numeric vector, should the result be a double instead?
In fact, I sent this ticket because my code broke after installing R 4.0.5 (from R 3.6.1) and the latest Tidyverse packages.
The lines below used to work:
df2 <- df %>%
add_row(x = "d",
y = 100 - summarise_if(., is.numeric, sum))
I fixed the code (and used the new function 'across'):
df1 <- df %>%
add_row(x = "d",
y = 100 - deframe(summarise(., across(where(is.numeric), sum)
)))
Frédéric.