pandoc version 1.12.3 or higher is required and was not found (R shiny)
Another option so that this works for all your R scripts is to define this variable globally.
On Debian/Ubuntu, add the following line to your .bashrc file:
export RSTUDIO_PANDOC=/usr/lib/rstudio/bin/pandoc
On macOS, add the following to your .bash_profile file:
export RSTUDIO_PANDOC=/Applications/RStudio.app/Contents/MacOS/pandoc
On Windows (using Git Bash), add the following to your .bashrc file:
export RSTUDIO_PANDOC="/c/Program Files/RStudio/bin/pandoc/"
The easiest way I solved this issue is to pass the Sys.setenv(..) command inside the crontab command prior to calling the RMarkdown::render. You need to separate the two commands with a semicolon:
R -e "Sys.setenv(RSTUDIO_PANDOC='/usr/lib/rstudio-server/bin/pandoc'); rmarkdown::render('File.Rmd', output_file='output.html')"
(Remember that the rstudio-server path differs from the non-server version)
Go into RStudio and find the system environment variable for RSTUDIO_PANDOC
Sys.getenv("RSTUDIO_PANDOC")
Then put that in your R script prior to calling the render command.
Sys.setenv(RSTUDIO_PANDOC="--- insert directory here ---")
This worked for me after I'd been struggling to find how rmarkdown finds pandoc. I had to check github to look at the source.