Compiler RecursionError more likely to occur in 3.13

[williamwen42]

Bug report

Bug description:

Reference: sympy/sympy#26692

There's a long expression in sympy that's causing a RecursionError in ast.c. The source of the RecursionError is

cpython/Python/ast.c

Line 217 in ffc8e21

PyErr_SetString(PyExc_RecursionError,

.

This seems to happen with a 3.13 debug build due to a lower recursion limit. The error doesn't happen in 3.13 release.

Interestingly, the error doesn't happen in the 3.12 debug build, even though the recursion limit appears to be the same. This leads me to believe that 3.13 is causing more recursive calls than expected. I think we should investigate why 3.13 is making additional calls and/or raise the recursion limit.

Simple repro:

import ast
contents = "x = " + " * ".join(["1"] * 2000)
result = ast.parse(contents)

On 3.12 debug, this code runs fine. On 3.13 debug, this code causes a RecursionError even when we change 2000 to 500 (leading me to believe that it is not the case that 3.13 is just adding a constant number of additional calls).

CPython versions tested on:

3.12, 3.13

Operating systems tested on:

Linux

[williamwen42]

Recursion limit set here

cpython/Include/cpython/pystate.h

Line 199 in 51bcb67

# define Py_C_RECURSION_LIMIT 500

for reference.