Skip threads test on the freethreading build

Author: oscarbenjamin

.github/workflows/buildwheel.yml

@@ -88,6 +88,12 @@ jobs:
         # and python-requires in pyproject.toml.
         python-version: ['3.11', '3.12', '3.13', '3.13t'] # , 'pypy3.10']
 
+        # XXX: Maybe this exclude can be removed when changing from
+        # Quansight-Labs/setup-python...
+        exclude:
+          - os: ubuntu-24.04-arm
+            python-version: '3.13t'
+
     steps:
       # Quansight-labs/setup-python is needed for 3.13t until a new version of
       # actions/setup-python (>5.4.0) is released.

src/flint/test/test_all.py

@@ -4739,6 +4739,21 @@ def test_fq_default_poly():
 
 
 def test_python_threads():
+    #
+    # https://github.com/flintlib/python-flint/issues/224
+    #
+    # XXX: This test crashes under the free-threading mode because of memory
+    # corruption.
+    #
+    # It is not clear if this should be fixed or if mutating
+    # matrices/polynomials that are shared between multiple threads should just
+    # be disallowed.
+    #
+
+    # Skip the test on the free-threaded build...
+    import sys
+    if sys.version_info[:2] >= (3, 13) and not sys._is_gil_enabled():
+        return
 
     from threading import Thread