> demanding new —yes-destroy-my-computer-dangerously-and-step-on-my-face-daddy flags and crashing my automated scripts from last year.

Literally, my case. I recently had to compile an abandoned six-year-old scientific package written in C with Python bindings. I wasn’t aware that modern versions of pip handle builds differently than they did six years ago — specifically, that it now compiles wheels within an isolated environment. I was surprised to see a message indicating that %package_name% was not installed, yet I was still able to import it. By the second day, I eventually discovered the --no-build-isolation option of pip.