"package 'foo' is not available" - What to do when R tells you it can't install a package

This common error means the package you’re looking for can’t be installed from CRAN. This is how you solve it. - The R language is infamous among its users for often having unhelpful error messages. One of the error messages that almost any R user in history has seen is “package ‘foo’ is not available (for R version x.y.z)”, which would come after trying to install package “foo” from CRAN using… …