The pkg_download_proposal and pkg_installation_proposal classes
both have download methods, to downloads package files into a
configured directory (see 'Configuration').
They return a pkg_download_result object, which is a data frame,
that adds extra columns to pkg_resolution_result (for
pkg_download_proposal) or pkg_solution_result
(for pkg_installation_proposal):
fulltarget: absolute path to the downloaded file. At most one of
fulltarget and fulltarget_tree must exist on the disk.
fulltarget_tree: absolute path to a package tree directory. At most
one of fulltarget and fulltarget_tree must exist on the disk.
download_status: "Had" or "Got", depending on whether the file
was obtained from the cache.
download_error: error object for failed downloads.
file_size: Size of the file, or NA. For installed:: refs, it is
NA, and it is also NA for refs that created fulltarget_tree
instead of fulltarget.
fulltarget, if it exists, contains a packaged (via R CMD build)
source R package. If fulltarget_tree exists, it is a package tree
directory, that still needs an R CMD build call.