By not using 'withCallingHandler' or 'tryCatch', the state is like 'stopifnot'
in R 3.4.x. If 'stopifnot' becomes faster than in R 3.4.x when the expressions
given to 'stopifnot' are all TRUE, it is because 'match.call' is not called.
Credit is to https://github.com/HenrikBengtsson/Wishlist-for-
The new staged package installation shells out to the 'file' utility
on Unix systems:
https://github.com/wch/r-source/blob/31ee14c620eb1b939acd322f3b5617f998aab8e8/src/library/tools/R/install.R#L578
Although 'file' is usually present on most Unix systems, it might be
missing from small Docker cont
