Other Options
Looking through ?options
it appears there are a couple that might produce the behavior you're looking for.
install.packages.compile.from.source
Setting install.packages.compile.from.source
to "interactive"
should prompt you for the decision interactively.
options(install.packages.compile.from.source = "interactive")
From the docs:
Used by install.packages(type = "both") (and indirectly update.packages) on platforms which support binary packages. Possible values are "never", "interactive" (which means ask in interactive use and "never" in batch use) and "always". The default is taken from environment variable R_COMPILE_AND_INSTALL_PACKAGES, with default "interactive" if unset. However, install.packages uses "never" unless a make program is found, consulting the environment variable MAKE.
pkgType
Another one to try as it appears to specify the behavior and wouldn't require interactive prompts.
options(pkgType = "win.binary")
From the docs:
pkgType:
The default type of packages to be downloaded and installed – see install.packages. Possible values are platform dependentlyon Windows: "win.binary", "source" and "both" (the default).