Issue #20532: Tests which use _testcapi now are marked as CPython only.
diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py
index 9013a7b..50c4bba 100644
--- a/Lib/test/test_capi.py
+++ b/Lib/test/test_capi.py
@@ -17,7 +17,8 @@
     import threading
 except ImportError:
     threading = None
-import _testcapi
+# Skip this test if the _testcapi module isn't available.
+_testcapi = support.import_module('_testcapi')
 
 
 def testfunction(self):