gh-152912: Fix audit hook exception check in sys.addaudithook()

sys.addaudithook() checks the exception from existing hooks against
PyExc_Exception instead of PyExc_RuntimeError. Any Exception
subclass is silently swallowed, blocking new hook installations
without propagating the error. The C API and documentation specify
RuntimeError only.

Author: k00shi

Lib/test/audit-tests.py

@@ -109,6 +109,16 @@ def test_block_add_hook_baseexception():
                 pass
 
 
+def test_block_add_hook_valueerror():
+    # Non-RuntimeError exceptions (like ValueError) should propagate out
+    with assertRaises(ValueError):
+        with TestHook(
+            raise_on_events="sys.addaudithook", exc_type=ValueError
+        ) as hook1:
+            with TestHook() as hook2:
+                pass
+
+
 def test_marshal():
     import marshal
     o = ("a", "b", "c", 1, 2, 3)

Misc/NEWS.d/next/Library/2026-07-03-02-11-00.gh-issue-152912.Mv3KpR.rst

@@ -0,0 +1 @@
+`sys.addaudithook()` now correctly suppresses only :exc:RuntimeError instead of all :exc:Exception subclasses when an existing audit hook raises during hook registration. Patch by Yeongu Kim.

Python/sysmodule.c

@@ -527,7 +527,7 @@ sys_addaudithook_impl(PyObject *module, PyObject *hook)
 
     /* Invoke existing audit hooks to allow them an opportunity to abort. */
     if (_PySys_Audit(tstate, "sys.addaudithook", NULL) < 0) {
-        if (_PyErr_ExceptionMatches(tstate, PyExc_Exception)) {
+        if (_PyErr_ExceptionMatches(tstate, PyExc_RuntimeError)) {
             /* We do not report errors derived from Exception */
             _PyErr_Clear(tstate);
             Py_RETURN_NONE;