Devtools :: build_vignettes gives' Error: invalid version specification 'pandoc.exe 1.13.1'

Question

After upgrading R to 3.1.2 and updating all the packages, I can no longer create vignettes.

devtools::build_vignettes(shdoe)

The output is as follows:

Building shdoe vignettes
Error : invalid version specification 'pandoc.exe 1.13.1'
Warning in engine$weave(file, quiet = quiet) :
  Pandoc is not available. Please install Pandoc.
Moving shdoe-intro.html, shdoe-intro.R to inst/doc/
Copying shdoe-intro.Rmd to inst/doc/

This is after updating pandoc version 1.12.x (which gave the same error). My OS is windows 7 and Pandoc is in PATH.

Answer 1

The problem is how knitr parses the version number returned

pandoc.exe --version

which includes the name by which pandoc is called:

pandoc.exe 1.13.1
[...]

R Sys.which('pandoc'), knitr, pandoc <PATH TO PANDOC>\pandoc.exe, pandoc, knitr.

knitr 1.7 ( , rmarkdown::pandoc_available(), pandoc).

, RSTUDIO_PANDOC <PATH TO PANDOC> ( knitr , ).