submit an R package with CTAN dependencies to CRAN - r

Question

I am currently working on an R package that is going to be submitted CRAN within a few weeks. The package needs some latex packages to run. Those latex packages are available on CTAN and injected in the preamble of RMarkdown documents via rmarkdown::latex_dependency().
This is the concept of my actual knit_print method.
#' #export
knit_print.my_class <- function(obj, ...) {
knitr::raw_latex(
to_latex(obj),
meta = list(
rmakrdown::latex_dependency(
"ragged2e"
)
)
)
}
My question is how those dependencies can be specified in a way such that CRAN is going to accept this submission. As far as I can tell, there are four options
submit the package as-is and add installation instructions via the documentation and the SystemRequirements field of the DESCRIPTION file.
include all necessary latex packages in my R package and somehow make them available to the client's latex compiler
add a dependency to tinytex which can install CTAN packages automatically
Throw an error during installation if the dependencies are not met
So far, I used option (1).
My configuration for travis (ubuntu 14.04) is
apt install texlive-latex-extra
tlmgr install standalone
For appveyor (Windows Server 2012 R2 x64), I unpack miktex-portable.exe and add it to the PATH. Then I get the following packages.
mpm --install=standalone
mpm --install=ms
mpm --install=pbox
mpm --install=xcolor
mpm --install=colortbl
mpm --install=mptopdf
What I found out so far
using google to search for external dependencies and CRAN sumbissions only yielded information about C and C++ dependencies, which didn't help my cause.
Looking at some source code revealed that rticles include certain .sty files directly in inst/ which leads me to believe, that (2) is the correct answer. However, rticles defines custom output formats and those don't have to "install" the latex packages since the .sty files are copied to the render directory as part of a template.
magick uses a config file that prevents the installation in case (system) dependencies are not met. It also throws an informative error message that instructs the client how the dependencies can be met.
the tinytex package did not run any compile tests on CRAN when it was submitted. I also can't make tinytex it work on appveyor

Answer 1

I am reasonably familiar with the CRAN Repository Policy and there is generally no provision for external dependencies off CRAN etc.
That said I stretched CRAN a little to by downloading pre-built libraries off GitHub as needed. You could model your package after that.
But what I really think you should do is to ... prepare your pdf vignette locally and then have the R package 'inject' it as is. How to do that is explained eg in this post by Mark and I just converted my RcppAnnoy package to do just that. Of course, YMMV.