diff --git a/requirements.txt b/requirements.txt
index bc8358b..c4c7fcc 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -21,4 +21,3 @@
 PrettyTable>=0.7.1 # BSD
 urllib3>=1.21.1 # MIT
 debtcollector>=1.2.0 # Apache-2.0
-unittest2>=1.1.0 # BSD
diff --git a/roles/run-tempest/README.rst b/roles/run-tempest/README.rst
index 0c72b69..1919393 100644
--- a/roles/run-tempest/README.rst
+++ b/roles/run-tempest/README.rst
@@ -81,7 +81,7 @@
 .. zuul:rolevar:: stable_constraints_file
    :default: ''
 
-   Upper constraints file to be used for stable branch till stable/stein.
+   Upper constraints file to be used for stable branch till stable/train.
 
 .. zuul:rolevar:: tempest_tox_environment
    :default: ''
diff --git a/roles/run-tempest/tasks/main.yaml b/roles/run-tempest/tasks/main.yaml
index a8b3ede..397de1e 100644
--- a/roles/run-tempest/tasks/main.yaml
+++ b/roles/run-tempest/tasks/main.yaml
@@ -25,11 +25,11 @@
     target_branch: "{{ zuul.override_checkout }}"
   when: zuul.override_checkout is defined
 
-- name: Use stable branch upper-constraints till stable/stein
+- name: Use stable branch upper-constraints till stable/train
   set_fact:
     # TOX_CONSTRAINTS_FILE is new name, UPPER_CONSTRAINTS_FILE is old one, best to set both
     tempest_tox_environment: "{{ tempest_tox_environment | combine({'UPPER_CONSTRAINTS_FILE': stable_constraints_file}) | combine({'TOX_CONSTRAINTS_FILE': stable_constraints_file}) }}"
-  when: target_branch in ["stable/ocata", "stable/pike", "stable/queens", "stable/rocky", "stable/stein"]
+  when: target_branch in ["stable/ocata", "stable/pike", "stable/queens", "stable/rocky", "stable/stein", "stable/train"]
 
 - name: Use Configured upper-constraints for non-master Tempest
   set_fact:
@@ -78,6 +78,17 @@
         exclude_list_option: "--exclude-list={{ tempest_test_exclude_list|quote }}"
       when: exclude_list_stat.stat.exists
 
+- name: stable/train workaround to fallback exclude-list to blacklist
+  # NOTE(gmann): stable/train use Tempest 26.1.0 and with stestr 2.5.1
+  # (beacause of upper constraints of stestr 2.5.1 in stable/train) which
+  # does not have new args exclude-list so let's fallback to old arg
+  # if new arg is passed.
+  set_fact:
+    exclude_list_option: "--blacklist-file={{ tempest_test_exclude_list|quote }}"
+  when:
+    - tempest_test_exclude_list is defined
+    - target_branch == "stable/train"
+
 # TODO(kopecmartin) remove this after all consumers of the role have switched
 # to tempest_exclude_regex option, until then it's kept here for the backward
 # compatibility
@@ -94,6 +105,19 @@
   when:
     - tempest_black_regex is not defined
     - tempest_exclude_regex is defined
+    - target_branch != "stable/train"
+
+- name: stable/train workaround to fallback exclude-regex to black-regex
+  # NOTE(gmann): stable/train use Tempest 26.1.0 and with stestr 2.5.1
+  # (beacause of upper constraints of stestr 2.5.1 in stable/train) which
+  # does not have new args exclude-regex so let's fallback to old arg
+  # if new arg is passed.
+  set_fact:
+    tempest_test_exclude_regex: "--black-regex={{tempest_exclude_regex|quote}}"
+  when:
+    - tempest_black_regex is not defined
+    - tempest_exclude_regex is defined
+    - target_branch == "stable/train"
 
 - name: Run Tempest
   command: tox -e {{tox_envlist}} {{tox_extra_args}} -- {{tempest_test_regex|quote}} \
diff --git a/tempest/common/compute.py b/tempest/common/compute.py
index 2443a67..5ba0a1a 100644
--- a/tempest/common/compute.py
+++ b/tempest/common/compute.py
@@ -57,7 +57,7 @@
 def create_test_server(clients, validatable=False, validation_resources=None,
                        tenant_network=None, wait_until=None,
                        volume_backed=False, name=None, flavor=None,
-                       image_id=None, wait_for_sshable=True, **kwargs):
+                       image_id=None, **kwargs):
     """Common wrapper utility returning a test server.
 
     This method is a common wrapper returning a test server that can be
@@ -93,8 +93,6 @@
         CONF.compute.flavor_ref will be used instead.
     :param image_id: ID of the image to be used to provision the server. If not
         defined, CONF.compute.image_ref will be used instead.
-    :param wait_for_sshable: Check server's console log and wait until it will
-        be ready to login.
     :returns: a tuple
     """
 
@@ -267,10 +265,6 @@
                             LOG.exception('Server %s failed to delete in time',
                                           server['id'])
 
-    if (validatable and CONF.compute_feature_enabled.console_output and
-            wait_for_sshable):
-        waiters.wait_for_guest_os_boot(clients.servers_client, server['id'])
-
     return body, servers
 
 
diff --git a/tempest/common/waiters.py b/tempest/common/waiters.py
index 21d0109..fbc8698 100644
--- a/tempest/common/waiters.py
+++ b/tempest/common/waiters.py
@@ -530,23 +530,6 @@
             raise lib_exc.TimeoutException(message)
 
 
-def wait_for_guest_os_boot(client, server_id):
-    start_time = int(time.time())
-    while True:
-        console_output = client.get_console_output(server_id)['output']
-        for line in console_output.split('\n'):
-            if 'login:' in line.lower():
-                return
-        if int(time.time()) - start_time >= client.build_timeout:
-            LOG.info("Guest OS on server %s probably isn't ready or its "
-                     "console log can't be parsed properly. If guest OS "
-                     "isn't ready, that may cause problems with SSH to "
-                     "the server.",
-                     server_id)
-            return
-        time.sleep(client.build_interval)
-
-
 def wait_for_server_floating_ip(servers_client, server, floating_ip,
                                 wait_for_disassociate=False):
     """Wait for floating IP association or disassociation.
diff --git a/tempest/lib/base.py b/tempest/lib/base.py
index 74ae77c..3be55c0 100644
--- a/tempest/lib/base.py
+++ b/tempest/lib/base.py
@@ -14,29 +14,11 @@
 #    under the License.
 
 import os
-import sys
 
 import fixtures
-import pkg_resources
 import testtools
 
 
-def _handle_skip_exception():
-    try:
-        stestr_version = pkg_resources.parse_version(
-            pkg_resources.get_distribution("stestr").version)
-        stestr_min = pkg_resources.parse_version('2.5.0')
-        new_stestr = (stestr_version >= stestr_min)
-        import unittest
-        import unittest2
-        if sys.version_info >= (3, 5) and new_stestr:
-            testtools.TestCase.skipException = unittest.case.SkipTest
-        else:
-            testtools.TestCase.skipException = unittest2.case.SkipTest
-    except Exception:
-        pass
-
-
 class BaseTestCase(testtools.testcase.WithAttributes, testtools.TestCase):
     setUpClassCalled = False
 
@@ -51,18 +33,6 @@
         if hasattr(super(BaseTestCase, cls), 'setUpClass'):
             super(BaseTestCase, cls).setUpClass()
         cls.setUpClassCalled = True
-        # TODO(gmann): cls.handle_skip_exception is really workaround for
-        # testtools bug- https://github.com/testing-cabal/testtools/issues/272
-        # stestr which is used by Tempest internally to run the test switch
-        # the customize test runner(which use stdlib unittest) for >=py3.5
-        # else testtools.run.- https://github.com/mtreinish/stestr/pull/265
-        # These two test runner are not compatible due to skip exception
-        # handling(due to unittest2). testtools.run treat unittestt.SkipTest
-        # as error and stdlib unittest treat unittest2.case.SkipTest raised
-        # by testtools.TestCase.skipException.
-        # The below workaround can be removed once testtools fix issue# 272.
-        cls.orig_skip_exception = testtools.TestCase.skipException
-        _handle_skip_exception()
 
     @classmethod
     def tearDownClass(cls):
@@ -70,7 +40,6 @@
             super(BaseTestCase, cls).tearDownClass()
 
     def setUp(self):
-        testtools.TestCase.skipException = self.orig_skip_exception
         super(BaseTestCase, self).setUp()
         if not self.setUpClassCalled:
             raise RuntimeError("setUpClass does not calls the super's "
diff --git a/tempest/scenario/test_network_qos_placement.py b/tempest/scenario/test_network_qos_placement.py
index adb0ee3..365eb1b 100644
--- a/tempest/scenario/test_network_qos_placement.py
+++ b/tempest/scenario/test_network_qos_placement.py
@@ -79,7 +79,7 @@
         new_flavor = self.flavors_client.create_flavor(**{
             'ram': old_flavor['ram'],
             'vcpus': old_flavor['vcpus'],
-            'name': old_flavor['name'] + 'extra',
+            'name': old_flavor['name'] + 'extra-%s' % data_utils.rand_int_id(),
             'disk': old_flavor['disk'] + 1
         })['flavor']
         self.addCleanup(test_utils.call_and_ignore_notfound_exc,
diff --git a/tempest/test.py b/tempest/test.py
index bf0aba4..dba2695 100644
--- a/tempest/test.py
+++ b/tempest/test.py
@@ -26,7 +26,6 @@
 from tempest.common import credentials_factory as credentials
 from tempest.common import utils
 from tempest import config
-from tempest.lib import base as lib_base
 from tempest.lib.common import api_microversion_fixture
 from tempest.lib.common import fixed_network
 from tempest.lib.common import profiler
@@ -142,19 +141,6 @@
         # It should never be overridden by descendants
         if hasattr(super(BaseTestCase, cls), 'setUpClass'):
             super(BaseTestCase, cls).setUpClass()
-        # All the configuration checks that may generate a skip
-        # TODO(gmann): cls.handle_skip_exception is really workaround for
-        # testtools bug- https://github.com/testing-cabal/testtools/issues/272
-        # stestr which is used by Tempest internally to run the test switch
-        # the customize test runner(which use stdlib unittest) for >=py3.5
-        # else testtools.run.- https://github.com/mtreinish/stestr/pull/265
-        # These two test runner are not compatible due to skip exception
-        # handling(due to unittest2). testtools.run treat unittestt.SkipTest
-        # as error and stdlib unittest treat unittest2.case.SkipTest raised
-        # by testtools.TestCase.skipException.
-        # The below workaround can be removed once testtools fix issue# 272.
-        orig_skip_exception = testtools.TestCase.skipException
-        lib_base._handle_skip_exception()
         try:
             cls.skip_checks()
 
@@ -182,8 +168,6 @@
                 raise value.with_traceback(trace)
             finally:
                 del trace  # to avoid circular refs
-        finally:
-            testtools.TestCase.skipException = orig_skip_exception
 
     @classmethod
     def tearDownClass(cls):
diff --git a/tempest/test_discover/test_discover.py b/tempest/test_discover/test_discover.py
index 5816ab1..a19f20b 100644
--- a/tempest/test_discover/test_discover.py
+++ b/tempest/test_discover/test_discover.py
@@ -13,15 +13,10 @@
 #    under the License.
 
 import os
-import sys
+import unittest
 
 from tempest.test_discover import plugins
 
-if sys.version_info >= (2, 7):
-    import unittest
-else:
-    import unittest2 as unittest
-
 
 def load_tests(loader, tests, pattern):
     ext_plugins = plugins.TempestTestPluginManager()
diff --git a/tempest/tests/common/test_waiters.py b/tempest/tests/common/test_waiters.py
index b76a263..5b0acfa 100755
--- a/tempest/tests/common/test_waiters.py
+++ b/tempest/tests/common/test_waiters.py
@@ -276,36 +276,6 @@
         )
         sleep.assert_called_once_with(client.build_interval)
 
-    def test_wait_for_guest_os_boot(self):
-        get_console_output = mock.Mock(
-            side_effect=[
-                {'output': 'os not ready yet\n'},
-                {'output': 'login:\n'}
-            ])
-        client = self.mock_client(get_console_output=get_console_output)
-        self.patch('time.time', return_value=0.)
-        sleep = self.patch('time.sleep')
-
-        with mock.patch.object(waiters.LOG, "info") as log_info:
-            waiters.wait_for_guest_os_boot(client, 'server_id')
-
-        get_console_output.assert_has_calls([
-            mock.call('server_id'), mock.call('server_id')])
-        sleep.assert_called_once_with(client.build_interval)
-        log_info.assert_not_called()
-
-    def test_wait_for_guest_os_boot_timeout(self):
-        get_console_output = mock.Mock(
-            return_value={'output': 'os not ready yet\n'})
-        client = self.mock_client(get_console_output=get_console_output)
-        self.patch('time.time', side_effect=[0., client.build_timeout + 1.])
-        self.patch('time.sleep')
-
-        with mock.patch.object(waiters.LOG, "info") as log_info:
-            waiters.wait_for_guest_os_boot(client, 'server_id')
-
-        log_info.assert_called_once()
-
 
 class TestVolumeWaiters(base.TestCase):
     vol_migrating_src_host = {
diff --git a/tempest/tests/lib/test_base.py b/tempest/tests/lib/test_base.py
index 2c16e1c..de6021c 100644
--- a/tempest/tests/lib/test_base.py
+++ b/tempest/tests/lib/test_base.py
@@ -48,7 +48,7 @@
     @classmethod
     def setUpClass(cls):  # noqa
         """Simulate absence of super() call."""
-        cls.orig_skip_exception = cls.skipException
+        pass
 
     def setUp(self):
         try:
diff --git a/tempest/tests/test_test.py b/tempest/tests/test_test.py
index a95914a..cbb81e2 100644
--- a/tempest/tests/test_test.py
+++ b/tempest/tests/test_test.py
@@ -14,7 +14,7 @@
 #    under the License.
 
 import os
-import sys
+import unittest
 from unittest import mock
 
 from oslo_config import cfg
@@ -34,12 +34,6 @@
 from tempest.tests.lib.services import registry_fixture
 
 
-if sys.version_info >= (2, 7):
-    import unittest
-else:
-    import unittest2 as unittest
-
-
 class LoggingTestResult(testtools.TestResult):
 
     def __init__(self, log, *args, **kwargs):