Unexpected rounding/formatting result/error when printing a tibble object

Start by running the supplied R example with pillar and tibble, then compare print(rounderr) with the stored values shown by View(). Trace the print path from the tibble's print method into pillar formatting. Done means determining whether the displayed Total value is incorrectly formatted and adding a regression test or documenting the expected result.

I have encountered an example of a tibble object being printed out, where the last (non-zero) digit appears to be wrongly truncated from the printing.

Here is the actual example R code which produces the issue. [I am using RStudio.]

library(tidyverse)
library(compositions)   # this is on CRAN

data(ArcticLake)  # from compositions package;  this is a matrix so convert to tibble below

rounderr <- ArcticLake |> 
             as_tibble() |> 
             mutate(Total = sand + silt + clay) |> 
             filter(abs(Total - 100.0) > 0.05) 

print(rounderr)

The output is

ArcticLakeTotalPrinting> source("~/Documents/Statistics/Research/ArcticLakeTotalPrinting/R/ArcticLakeTotalBug.R")
── Attaching core tidyverse packages ────────────────────────────────────────────────────────────── tidyverse 2.0.0 ──
✔ dplyr     1.1.4     ✔ readr     2.1.5
✔ forcats   1.0.0     ✔ stringr   1.5.1
✔ ggplot2   3.5.1     ✔ tibble    3.2.1
✔ lubridate 1.9.3     ✔ tidyr     1.3.1
✔ purrr     1.0.2     
── Conflicts ──────────────────────────────────────────────────────────────────────────────── tidyverse_conflicts() ──
✖ dplyr::filter() masks stats::filter()
✖ dplyr::lag()    masks stats::lag()
ℹ Use the conflicted package to force all conflicts to become errors
Welcome to compositions, a package for compositional data analysis.
Find an intro with "? compositions"


Attaching package: ‘compositions’

The following objects are masked from ‘package:stats’:

    anova, cor, cov, dist, var

The following object is masked from ‘package:graphics’:

    segments

The following objects are masked from ‘package:base’:

    %*%, norm, scale, scale.default

# A tibble: 5 × 5
   sand  silt  clay depth Total
  <dbl> <dbl> <dbl> <dbl> <dbl>
1  52.2  40.9   6.6  13    99.7
2   4.8  54.7  41    49.5 100. 
3   7.4  51.6  40.9  73.6  99.9
4   6.7  47.3  45.9  87.7  99.9
5   7.4  45.6  46.9  88.1  99.9

The last column in the second row should be 100.5. But clearly it has lost the tenths digit.

Using the View() function, I could explore the structure of the tibble in question visually. Here is a screenshot to show that the relevant value is actually stored correctly.

I checked the help pages, expecting to see this was a consequence of a pure '.5' being rounded, which is somewhat more subtle than run-of-the-mill rounding. I could not find any such information -- obviously if I have missed this I would be very grateful to have it pointed out!

Here is sessionInfo():

ArcticLakeTotalPrinting> sessionInfo()
R version 4.4.1 (2024-06-14)
Platform: x86_64-apple-darwin20
Running under: macOS Sonoma 14.6.1

Matrix products: default
BLAS:   /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib 
LAPACK: /Library/Frameworks/R.framework/Versions/4.4-x86_64/Resources/lib/libRlapack.dylib;  LAPACK version 3.12.0

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

time zone: America/New_York
tzcode source: internal

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

other attached packages:
 [1] compositions_2.0-8 lubridate_1.9.3    forcats_1.0.0      stringr_1.5.1      dplyr_1.1.4        purrr_1.0.2       
 [7] readr_2.1.5        tidyr_1.3.1        tibble_3.2.1       ggplot2_3.5.1      tidyverse_2.0.0   

loaded via a namespace (and not attached):
 [1] gtable_0.3.5        compiler_4.4.1      Rcpp_1.0.13         tidyselect_1.2.1    tinytex_0.53       
 [6] bayesm_3.1-6        scales_1.3.0        R6_2.5.1            generics_0.1.3      robustbase_0.99-4-1
[11] MASS_7.3-61         munsell_0.5.1       pillar_1.9.0        tzdb_0.4.0          rlang_1.1.4        
[16] utf8_1.2.4          Rttf2pt1_1.3.12     stringi_1.8.4       xfun_0.44           timechange_0.3.0   
[21] cli_3.6.3           withr_3.0.1         magrittr_2.0.3      grid_4.4.1          rstudioapi_0.16.0  
[26] hms_1.1.3           lifecycle_1.0.4     DEoptimR_1.1-3      vctrs_0.6.5         extrafont_0.19     
[31] tensorA_0.36.2.1    glue_1.8.0          extrafontdb_1.0     fansi_1.0.6         colorspace_2.1-1   
[36] tools_4.4.1         pkgconfig_2.0.3   

Here is my RStudio info:

RStudio 2024.09.0+375 "Cranberry Hibiscus" Release (c8fc7aee6dc218d5687553f9041c6b1e5ea268ff, 2024-09-16) for macOS
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) RStudio/2024.09.0+375 Chrome/124.0.6367.243 Electron/30.4.0 Safari/537.36, Quarto 1.5.57 (/Applications/quarto/bin/quarto)