I am encountering a really strange bug in rendering plain lists in Rmarkdown. Interestingy, I can only reproduce if R (or Rscript) is running non-interactively.
Consider this file (save as test_rmarkdown.Rmd):
---
title: Rmarkdown Test
---
```{r, message = FALSE}
library("dplyr")
library("report")
```
```{r, results = "asis"}
iris %>%
dplyr::select(Petal.Length, Species, everything()) %>%
dplyr::rename(Spe = Species) %>%
report::report(iris) %>%
summary()
```
```{r, comment = '', results = "markup"}
sessionInfo()
```
When I render this file using
rmarkdown::render('test_rmarkdown.Rmd', 'html_document')
The output is as expected.
However, when I render this file using
system("Rscript -e \"require(rmarkdown); rmarkdown::render('test_rmarkdown.Rmd', 'html_document')\"")
# or directly from the shell, and with the same result using `R` instead of `Rscript`
I get a broken list, as in the test_rmarkdown.md there is a hard wrapped line break:
The data contains 150 observations of the following 5 variables:
- Petal.Length: n = 150, Mean = 3.76, SD = 1.77, range: [1, 6.90]
- Spe: 3 levels, namely setosa (n = 50), versicolor (n = 50) and virginica (n =
50)
- Sepal.Length: n = 150, Mean = 5.84, SD = 0.83, range: [4.30, 7.90]
- Sepal.Width: n = 150, Mean = 3.06, SD = 0.44, range: [2, 4.40]
- Petal.Width: n = 150, Mean = 1.20, SD = 0.76, range: [0.10, 2.50]
I do not even know, who is to blame. knitr ?
Can someone confirm? And could someone explain what goes wrong here?
Thanks in advance!
PS: There is a work-around: Using cat works even when compiling non-interactively:
```{r, results = "asis"}
iris %>%
dplyr::select(Petal.Length, Species, everything()) %>%
dplyr::rename(Spe = Species) %>%
report::report(iris) %>%
summary() %>%
paste0("\n") %>%
cat
```
PPS: Here is the sessionInfo:
R version 4.5.0 (2025-04-11)
Platform: x86_64-pc-linux-gnu
Running under: CentOS Linux 7 (Core)
Matrix products: default
BLAS/LAPACK: /opt/intel/oneapi/mkl/2023.0.0/lib/intel64/libmkl_gf_lp64.so.2; LAPACK version 3.10.1
locale:
[1] LC_CTYPE=en_US.utf8 LC_NUMERIC=C
[3] LC_TIME=en_US.utf8 LC_COLLATE=en_US.utf8
[5] LC_MONETARY=en_US.utf8 LC_MESSAGES=en_US.utf8
[7] LC_PAPER=en_US.utf8 LC_NAME=C
[9] LC_ADDRESS=C LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_US.utf8 LC_IDENTIFICATION=C
time zone: Europe/Berlin
tzcode source: system (glibc)
attached base packages:
[1] stats graphics grDevices datasets utils methods base
other attached packages:
[1] report_0.6.1 dplyr_1.1.4 rmarkdown_2.29
loaded via a namespace (and not attached):
[1] vctrs_0.6.5 cli_3.6.5 knitr_1.50 rlang_1.1.6
[5] xfun_0.52 renv_1.1.4 generics_0.1.4 jsonlite_2.0.0
[9] glue_1.8.0 htmltools_0.5.8.1 sass_0.4.10 datawizard_1.1.0
[13] evaluate_1.0.4 jquerylib_0.1.4 tibble_3.3.0 fastmap_1.2.0
[17] yaml_2.3.10 lifecycle_1.0.4 insight_1.3.0 compiler_4.5.0
[21] pkgconfig_2.0.3 digest_0.6.37 R6_2.6.1 tidyselect_1.2.1
[25] pillar_1.10.2 magrittr_2.0.3 bslib_0.9.0 withr_3.0.2
[29] tools_4.5.0 cachem_1.1.0
Set the line width before rendering
system("Rscript -e \"require(rmarkdown); options('width'=100); rmarkdown::render('test_rmarkdown.Rmd', 'html_document')\"")
There's nothing to blame. knitr is doing a nice thing and avoiding overriding width on its own.
Perhaps the blame should be on the default value of width in R. It is 72.