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FAIL: setUpClass (tempest.api.volume.admin.test_volume_types_negative.VolumeTypesNegativeV1Test)
tags: worker-0
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Traceback (most recent call last):
  File "/var/lib/tempest/tempest/test.py", line 249, in setUpClass
    cls.resource_setup()
  File "/var/lib/tempest/tempest/api/volume/base.py", line 156, in resource_setup
    super(BaseVolumeAdminTest, cls).resource_setup()
  File "/var/lib/tempest/tempest/api/volume/base.py", line 43, in resource_setup
    cls.os = cls.get_client_manager()
  File "/var/lib/tempest/tempest/test.py", line 334, in get_client_manager
    force_tenant_isolation=force_tenant_isolation,
  File "/var/lib/tempest/tempest/common/credentials.py", line 39, in get_isolated_credentials
    return accounts.NotLockingAccounts(name=name)
  File "/var/lib/tempest/tempest/common/accounts.py", line 48, in __init__
    self.accounts_dir = os.path.join(CONF.lock_path, 'test_accounts')
  File "/usr/lib/python2.7/posixpath.py", line 77, in join
    elif path == '' or path.endswith('/'):
AttributeError: 'NoneType' object has no attribute 'endswith'
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