Is it possible to run callr::r with a different R version than the one currently used? An example would be to call the following from R3.5.1, but execute it with R3.4.1.
callr::r(
func = R.version.string,
r_binary = '..../R3.4.1/bin' # inexistent argument
)
It should return something like "3.4.1". I have looked into callr:::setup_r_binary_and_args, but it takes the current R version.