The lockbox package keeps a secret directory with the packages for
each given version. By default, this is in
getOption("lockbox.lib")
or "~/.R/lockbox"
if that option
is not set.
"ensure_package_exists_in_lockbox!"(locked_package)
locked_package. In particular, name
and
version
elements will be used. If the package version is
not present in the lockbox, we will attempt to download it from
CRAN or github.