diff -Nur pytest-mock-1.10.0/test_pytest_mock.py pytest-mock-1.10.0_bak/test_pytest_mock.py
--- pytest-mock-1.10.0/test_pytest_mock.py	2018-05-02 01:10:54.000000000 +0800
+++ pytest-mock-1.10.0_bak/test_pytest_mock.py	2021-06-03 16:34:18.277654058 +0800
@@ -12,6 +12,9 @@
 skip_pypy = pytest.mark.skipif(platform.python_implementation() == 'PyPy',
                                reason='could not make work on pypy')
 
+#Python 3.8 changed the output formatting (bpo-35500), which has been ported to mock 3.0
+NEW_FORMATTING = sys.version_info >= (3, 8) or sys.version_info[0] == 2
+
 
 @pytest.fixture
 def needs_assert_rewrite(pytestconfig):
@@ -179,7 +182,11 @@
 
     def __test_failure_message(self, mocker, **kwargs):
         expected_name = kwargs.get('name') or 'mock'
-        expected_message = 'Expected call: {0}()\nNot called'.format(expected_name)
+        if NEW_FORMATTING:
+            msg = "expected call not found.\nExpected: {0}()\nActual: not called."
+        else:
+            msg = "Expected call: {0}()\nNot called"
+        expected_message = msg.format(expected_name)
         stub = mocker.stub(**kwargs)
         with pytest.raises(AssertionError) as exc_info:
             stub.assert_called_with()
@@ -559,20 +566,30 @@
             m.assert_called_once_with('', bar=4)
     """)
     result = testdir.runpytest('-s')
-    result.stdout.fnmatch_lines([
-        "*AssertionError: Expected call: mock('', bar=4)*",
-        "*Actual call: mock('fo')*",
+    if NEW_FORMATTING:
+        expected_lines = [
+            "*AssertionError: expected call not found.",
+            "*Expected: mock('', bar=4)",
+            "*Actual: mock('fo')",
+        ]
+    else:
+        expected_lines = [
+            "*AssertionError: Expected call: mock('', bar=4)*",
+            "*Actual call: mock('fo')*",
+        ]
+    expected_lines += [
         "*pytest introspection follows:*",
-        '*Args:',
+        "*Args:",
         "*assert ('fo',) == ('',)",
         "*At index 0 diff: 'fo' != ''*",
         "*Use -v to get the full diff*",
         "*Kwargs:*",
         "*assert {} == {'bar': 4}*",
-        "*Right contains more items:*",
+        "*Right contains* more item*",
         "*{'bar': 4}*",
         "*Use -v to get the full diff*",
-    ])
+    ]
+    result.stdout.fnmatch_lines(expected_lines)
 
 
 def test_assert_called_with_unicode_arguments(mocker):
diff -Nur pytest-mock-1.10.0/tox.ini pytest-mock-1.10.0_bak/tox.ini
--- pytest-mock-1.10.0/tox.ini	2018-05-02 01:10:54.000000000 +0800
+++ pytest-mock-1.10.0_bak/tox.ini	2021-06-03 15:57:02.000000000 +0800
@@ -12,7 +12,7 @@
 
 [testenv:norewrite]
 commands =
-    pytest test_pytest_mock.py --assert=plain -ra
+    pytest test_pytest_mock.py --assert=plain
 
 [testenv:linting]
 skip_install=True
@@ -23,3 +23,9 @@
 commands =
     py.test --flakes pytest_mock.py test_pytest_mock.py -m flakes
     rst-lint CHANGELOG.rst README.rst
+
+[tool:pytest]
+addopts = -r a
+
+[flake8]
+max-line-length = 88