coolbutuseless, 
Has anyone ever written a "multi-facetted" package for CRAN?
For example, I have a package that uses the connections API.
I would like the full version available from GitHub and r-universe.
Through clever use of defines and 'if' statements etc, the CRAN version would exclude all forbidden code.
Could this exist in one pkg tarball? Or would the tarballs have to be different?
Are there CRAN-specific ENV vars that can be used to control the inclusion/exclusion of code?