[R-pkg-devel] Avoid reprocessing Rmd vignette

[Johannes Ranke]

...

> The idea exposed by Dirk is the same: requireNamespace will find the
> package on CRAN and will set eval=TRUE. What you want though is to
> avoid running a chunk on CRAN, even if the package is available. So
> you need to set eval=FALSE *unconditionally*.

Or conditional on the package version (as Dirk proposed regarding tests) or on 
an environment variable NOT_CRAN which you can set to true on the machine 
where you do want to run the code (as used by devtools).

Johannes