What are you doing here that causes intermediate Markdown of your vignettes to be left behind? I have enabled the Vignettes roclet in Project Build Options in RStudio and it's being run when I document my package, but I'm only getting vignette.Rmd --> vignette.R and vignette.html. No vignette.md😢
I wouldn't have expected that the intermediate vignette.md is kept around @jennybc as this isn't the default behavior in build_vignettes. AFAIK build_vignettes only does as you describe, keeping the .R and .html output, and discarding the .md.
Very much a guess (I only started to read up on creating vignettes in the last day) but maybe you can retain the intermediate files by using rmarkdown::render from the Rstudio console. I think render is used "underneath the hood" to generate vignettes.
There is an argument clean which defaults to TRUE, but if set to FALSE seems to leave heaps of intermediate stuff lying round.
clean TRUE to clean intermediate files created during rendering.
Maybe that would get what you are looking for? Not quite as painless as running from the RStudio buttons and menus, but it might work. (I tried on a dummy example and got some .md files, but not able to tell if they are the ones you want.) If I discover an easier or more elegant method I'll update this set of comments. (I have yet to read up on the vignettes roclet).
Thanks @Geoff99. I'm pretty well-versed in the usage of rmarkdown::render. What I'm getting at here is whether I'm overlooking some new way to get intermediate .md for free when I automate package development tasks, such as updating docs.
Thanks again @Geoff99. Your message prompted me to be more bold re: modifying the YAML of my R Markdown vignette, as I would with any other .Rmd document. So this YAML now gets me my intermediate Markdown without any manual intervention. YAY.
Glad I was able to help in some small way @jennybc , even though I didn't have the right answer. I've learnt something new from your solution and will add looking into YAML more closely to my "to learn about" list.