`:(exclude)**/__pycache__/**` reads as "exclude any __pycache__" and is not. Without
`glob` magic git will not let `**` span ZERO directories, so the pattern hid a nested
__pycache__ and missed one at the repo root — which is exactly where pytest puts it for
a flat repo. Every grind diff has been carrying a .pyc; @reviewer flagged the symptom on
the modeltag grind, and `git diff --stat` against both spellings shows the mechanism.
The failure is invisible by inspection, since both spellings say the same thing in
English. So tests/test_grind_noise.py builds a real git repo with real scratch and diffs
it with the real pathspec list: red on the old spelling for the top-level case only,
green on the new one, ~30 ms, no model. NOISE moved to module level to be testable at all.
Also normalised pytest-of-* and .pytest_cache to the same **/…/** + glob form; they were
top-level-only patterns and would have missed a nested occurrence.
marfrit
2cf4ec3778