After upgrading R to 3.1.2 and updating all packages I can no longer build 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 an update of pandoc from version 1.12.x (which yielded the same error). My OS is windows 7, and Pandoc is on the PATH.