reposoption in callr subprocesses
callr sets the
repos option in subprocesses, to make sure that
a CRAN mirror is set up. This is because the subprocess cannot bring
up the menu of CRAN mirrors for the user to choose from.
Named character vector, the default value of the
option in callr subprocesses.
default_repos()#> CRAN #> "https://cloud.r-project.org"