Printouts of grouped tibbles in notebooks lack grouping variable information

rmarkdown

#1

When working in a script file, standard data frames, tibbles, and grouped tibbles all print differently to the console. In a notebook, when printing output from multiple function calls, a grouped tibble yields results that are labeled as "grouped_df" in the icons that represent each piece of output, but the information regarding which variables they're grouped by is missing. If the only output in a chunk is the printout of a grouped tibble, there's no indication at all that it's grouped. Is that a bug, or by design? Or am I missing something simple that's suppressing it?

Running the example below in a script window and then in an rmd window will demonstrate how different the two displays are.

Thanks,
Bob

group <- c("A","A","B","B")
x <- 1:4
my_df <- data.frame(group, x, stringsAsFactors = FALSE)

library("dplyr")
my_tibble <- data_frame(group, x)
my_tibble_grouped <-
  my_tibble %>% 
  group_by(group)

print(my_df)
print(my_tibble)
print(my_tibble_grouped)

sessionInfo()
R version 3.5.1 (2018-07-02)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)

Matrix products: default

locale:
[1] LC_COLLATE=English_United States.1252 LC_CTYPE=English_United States.1252
[3] LC_MONETARY=English_United States.1252 LC_NUMERIC=C
[5] LC_TIME=English_United States.1252

attached base packages:
[1] stats graphics grDevices utils datasets methods base

other attached packages:
[1] dplyr_0.7.6

loaded via a namespace (and not attached):
[1] Rcpp_0.12.18 fansi_0.3.0 utf8_1.1.4 crayon_1.3.4 assertthat_0.2.0 R6_2.2.2
[7] magrittr_1.5 pillar_1.3.0 cli_1.0.0 rlang_0.2.1 rstudioapi_0.7 bindrcpp_0.2.2
[13] tools_3.5.1 glue_1.3.0 purrr_0.2.5 compiler_3.5.1 pkgconfig_2.0.1 knitr_1.20
[19] bindr_0.1.1 tidyselect_0.2.4 tibble_1.4.2