CRAN check: warning vignette engine knitr::rmarkdown is not available

Question

I'm trying for the first time to add some vignettes in my package. Everything is ok on my computer. No warning, no error. Then I uploaded it to the CRAN windows builder

devtools::check_win_release()

And I got this warning relative to vignettes:

* checking re-building of vignette outputs ... [7s] WARNING
Error in re-building vignettes:
  ...
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  The vignette engine knitr::rmarkdown is not available, because the rmarkdown package is not installed. Please install it.
Failed with error:  'there is no package called 'rmarkdown''
Quitting from lines 172-178 (las.Rmd) 
Error: processing vignette 'las.Rmd' failed with diagnostics:
cannot open the connection
Execution halted

I don't think that this issue is related to the content of the package. Can I assume that it is an "ok" warning? Can I fix it?

My DESCRIPTION file contains:

Suggests: knitr
VignetteBuilder: knitr

• My vignettes/ folder contains one Rmd file
• My inst/doc/ folder contains the Rmd R and html auto generated files relative the the original Rmd file.

Answer 1

You need to add rmarkdown in your Suggests.