If you force the LLM to solve every test failure this also can lead to the same breakdown models as very junior developers coding to the tests rather than the problems, I've seen all of:

1) I broke the tests, guess I should delete them.

2) I broke the tests, guess the code I wrote was wrong, guess I should delete all of that code I wrote.

3) I broke the tests, guess I should keep adding more code and scaffolding. Another abstraction layer might work? What if I just add skeleton code randomly, does this add random code whack-a-mole work?

That last one can be particularly "fun" because already verbose LLM code skyrockets into baroque million line PRs when left truly unsupervised, and that PR still won't build or pass tests.

There's no true understanding by an LLM. Forcing it to lint/build can be important/useful, but still not a cure-all, and leads to such fun even more degenerate cases than hand-holding it.