how do I make install.packages return an error if an R package cannot be installed?

Question

install.packages() returns a warning if a package cannot be installed (for instance, if it is unavailable); for example:

install.packages(\"nota         


        

Answer 1

The R function WithCallingHandlers() lets us handle any warnings with an explicitly defined function. For instance, we can tell the R to stop if it receives any warnings (and return the warning message as an error message).

withCallingHandlers(install.packages("notapackage"),
                    warning = function(w) stop(w))

I am guessing that this is not ideal, since presumably a package could install successfully but still throw a warning; but haven't encountered that case. As Dirk suggests, testing require for the package is probably more robust.