[R-pkg-devel] Disable a particular knitr vignette

[Iñaki Úcar]

Hi everyone,

I have a JSS vignette based on the rticles package. It was compiling
just fine until rticles v0.5 for some reason started requiring pandoc
v2.x for such a document class, and failing otherwise. Due to this
requirement, Windows machines on CRAN show a nasty WARN, because they
still have pandoc v1.x.

It is painful for Uwe to install pandoc v2.x there, so I was wondering
whether there's any easy mechanism to just disable a particular
vignette based on some condition (in this case, it would be "we are on
CRAN, this is Windows and the pandoc version is < 2"; this is easy to
test).

I tried putting a condition for the output format in the YAML header
and it works, i.e.:

output: if (cond) rticles::jss_article else rmarkdown::pdf_document

But rmarkdown::pdf_document fails to compile, because the JSS class
has many custom macros. I tried also putting a NULL or a NA there, and
it doesn't work.

Does any knitr ninja here know if there's some easy trick to do this
and make Uwe's life easier? Some "NULL" document format?

Regards,
Iñaki