I’ve had some brief run-ins with R, and it doesn’t surprise me that it doesn’t have a versioning story for packages, and that the patched-in system described here is based on dates rather than something like a SHA or version number...

My favorite description of the language comes from http://arrgh.tim-smith.us/:

> R is a shockingly dreadful language for an exceptionally useful data analysis environment.

I feel like this is just one more data point to support that statement.