I just tried to install a package with knitr (.Rnw) vignettes in the 'vignettes' directory, and the vignettes were not built because I had forgotten to install the "knitr" package. R passed over this error silently:
$ R CMD build .
* checking for file ‘./DESCRIPTION’ ... OK
* preparing ‘DESeq2paper’:
* checking DESCRIPTION meta-information ... OK
* checking for LF line-endings in source and make files
* checking for empty or unneeded directories
* looking to see if a ‘data/datalist’ file should be added
* creating default NAMESPACE file
* building ‘DESeq2paper_1.0.tar.gz’
It would be good if R issued an error message (or at least a warning) if building a vignette is not possible because the vignette building engine specified in the "VignetteBuilder" line of the description field is not installed.
"... of the DESCRIPTION file ...", I meant to write
There can be more than one engine.
If any of them are missing, R CMD build now gives an error.