Of course, there is a third way: just run
strip --strip-debugover all the shared libraries after the build. As the path is standardized, and the shell does proper globbing, we can just do
$ strip --strip-debug /usr/local/lib/R/site-library/*/libs/*.so
using a double-wildcard to get all packages (in that R package directory) and all their shared libraries. Users on macOS probably want
.dylibon the end, users on Windows want another computer as usual (just kidding: use
.dll). Either may have to adjust the path which is left as an exercise to the reader.
When running this against the tidyverse library, shared library sizes dropped from 78 MB down to 6.6 MB. Not bad for a single command. H/T R-Bloggers