[R-SIG-Mac] checking for pdflatex

[JJ Allaire]

>
> I guess that would be less disruptive. If the user has picked a custom order at least it would be preserved. But as noted earlier I also think that this should be better fixed in rmarkdown - preferably by using the full path so it doesn't depend on PATH. I'm told RStudio is providing pandoc binaries so I would guess it's easy for them to guarantee the functionality but JJ is included so he can weigh in.

rmarkdown calls pandoc which in turn calls pdflatex. We have some
logic to discover the path to pdflatex and forward that on to pandoc
here:

https://github.com/rstudio/rmarkdown/blob/master/R/util.R#L186-L203

I'm not sure in this particular case why the right version isn't
found. What happens if you call rmarkdown:::find_program("pdflatex")
from the R prompt.

Would be happy to make any change you suggest to the way we forward
paths on to pandoc in order to make this work.