diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py
--- a/Lib/test/test_capi.py
+++ b/Lib/test/test_capi.py
@@ -482,9 +482,12 @@
     def test__testcapi(self):
         for name in dir(_testcapi):
             if name.startswith('test_'):
-                with self.subTest("internal", name=name):
-                    test = getattr(_testcapi, name)
-                    test()
+                try:
+                    with self.subTest("internal", name=name):
+                        test = getattr(_testcapi, name)
+                        test()
+                except unittest.SkipTest:
+                    pass
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/Lib/unittest/case.py b/Lib/unittest/case.py
--- a/Lib/unittest/case.py
+++ b/Lib/unittest/case.py
@@ -10,6 +10,7 @@
 import collections
 import contextlib
 import traceback
+import os
 
 from . import result
 from .util import (strclass, safe_repr, _count_diff_all_purpose,
@@ -360,6 +361,11 @@
 
     _classSetupFailed = False
 
+    if 'SUBTEST_RANGE' in os.environ:
+        subtest_range = eval(os.environ['SUBTEST_RANGE'])
+    else:
+        subtest_range = None
+
     def __init__(self, methodName='runTest'):
         """Create an instance of the class that will use the named test
            method when executed. Raises a ValueError if the instance does
@@ -380,6 +386,7 @@
             self._testMethodDoc = testMethod.__doc__
         self._cleanups = []
         self._subtest = None
+        self.count = 0
 
         # Map types to custom assertEqual functions that will compare
         # instances of said type in more detail to generate a more useful
@@ -494,6 +501,14 @@
             params_map = parent.params.new_child(params)
         self._subtest = _SubTest(self, msg, params_map)
         try:
+            self.count += 1
+            if self.subtest_range is not None:
+                if (self.subtest_range and
+                        self.count not in self.subtest_range):
+                    raise SkipTest('Sub test number not in range.')
+                pfx = 'subTest# %d: %s,' % (self.count, msg)
+                print(pfx, str(params)[:79-len(pfx)])
+
             with self._outcome.testPartExecutor(self._subtest, isTest=True):
                 yield
             if not self._outcome.success:
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -2715,7 +2715,7 @@
 test_incref_decref_API(PyObject *ob)
 {
     PyObject *obj = PyLong_FromLong(0);
-    Py_IncRef(obj);
+    Py_IncRef(ob);
     Py_DecRef(obj);
     Py_DecRef(obj);
     Py_RETURN_NONE;