I think one could get most of the way there by having a bot that: a) Autobuilds the library based on its declared dependency stack. b) Runs a test suite, and re

I think one could get most of the way there by having a bot that: a) Autobuilds the library based on its declared dependency stack. b) Runs a test suite, and reports back breakage. Anything that sits broken more than (say) a month can safely be considered dead. Super-stable low-level code will continue passing their tests forever, and things dependent on specific API versioning in left_pad will be marked dead quickly...