Faster Mathics3 exits

pyproject.toml

@@ -74,6 +74,7 @@ dev = [
     "pexpect",
     "pre-commit",
     "pytest",
+    "pytest-benchmark",
 ]
 full = [
     "ipywidgets",

test/conftest.py

@@ -0,0 +1,11 @@
+# Code that gets run before pytest runs..
+import gc
+
+
+def pytest_sessionfinish(session, exitstatus):
+    """Executes after all tests have completed.
+
+    Freeze objects right before pytest exits. This prevents PyGC_Collect from
+    walking Generation 2 objects during _Py_Finalize.
+    """
+    gc.freeze()