install.packages() ignoring option to convert warning to error? - r

Question

I'm trying to find a simple way to make install.packages() throw an error if it fails (rather than just a warning).
What I've tried
Setting options(warn=2) converts warnings into errors. Example:
options(warn=2)
warning()
# Error: (converted from warning)
I expected this would now error:
install.packages('thispackagedoesntexist')
# Warning in install.packages :
# package ‘thispackagedoesntexist’ is not available for this version of R
#
# A version of this package for your version of R might be available elsewhere,
# see the ideas at
# https://cran.r-project.org/doc/manuals/r-patched/R-admin.html#Installing-packages
yet it still just gives a warning (no error).
Question
How can install.packages() be made to error (rather than simply warn) on any sort of failure?
Note:
There are a few nice ways of making install.packages() error instead of warning, but I'm scouting for something much more lightweight, preferably without installing other packages, which options() would achieve nicely (if I can get it working).

Answer 1

This is an RStudio "feature".
First I wondered why the warning isn't printed in red. Then I looked at install.packages (in RStudio) and saw this:
> install.packages
function (...)
.rs.callAs(name, hook, original, ...)
<environment: 0x1408432c8>
> getAnywhere(.rs.callAs)
A single object matching ‘.rs.callAs’ was found
It was found in the following places
tools:rstudio
with value
function (name, f, ...)
{
withCallingHandlers(tryCatch(f(...), error = function(e) {
cat("Error in ", name, " : ", e$message, "\n", sep = "")
}), warning = function(w) {
if (getOption("warn") >= 0)
cat("Warning in ", name, " :\n ", w$message, "\n",
sep = "")
invokeRestart("muffleWarning")
})
}
<environment: 0x1181b4928>
See how warnings are handled and how the printed "warning" isn't actually a warning but cat output?
If I run your code in Rgui, I see this:
> options(warn=2)
> install.packages('thispackagedoesntexist')
Error: (converted from warning) package ‘thispackagedoesntexist’ is not available for this version of R
A version of this package for your version of R might be available elsewhere,
see the ideas at
https://cran.r-project.org/doc/manuals/r-patched/R-admin.html#Installing-packages
So, I suggest you go to the RStudio developers and complain that they use cat to misleadingly print "errors" and "warnings".
You can avoid RStudio's masking of install.packages the usual way:
> options(warn=2)
> utils::install.packages('thispackagedoesntexist')
Error: (converted from warning) package ‘thispackagedoesntexist’ is not available for this version of R
A version of this package for your version of R might be available elsewhere,
see the ideas at
https://cran.r-project.org/doc/manuals/r-patched/R-admin.html#Installing-packages