@timbray
This brings to mind the section of the 1982 Adm. Grace Hopper lecture (then Capt.) about a mathematical treatment of analyzing code change propagation.
Starts here:
https://youtu.be/AW7ZHpKuqZg?t=938
and in particular here
https://youtu.be/AW7ZHpKuqZg?t=1072
where she talks about the system never stabilizing.
Of course the answer is to lock down the inter-module interfaces and subject them to a more rigorous change management. Hard to do with wild-west libraries.