This was reported here: https://discuss.python.org/t/has-sys-setrecursionlimit-behaviour-changed-in-python-3-12b/30205

The following program works fine on 3.11, but crashes with RecursionError on 3.12:

d = {}
for x in range(1_000):
    d = {'k': d}

import json, sys
sys.setrecursionlimit(100_000_000)
foo = json.dumps(d)

I confirmed this bisects to #96510

Linked PRs

• GH-107263: Increase C stack limit for most functions, except _PyEval_EvalFrameDefault() #107535
• [3.12] GH-107263: Increase C stack limit for most functions, except _PyEval_EvalFrameDefault() (GH-107535) #107618