def METHOD_NAME(topology_st_gssapi, testuser):
    """Test that auth fails when we can not map a user.
    :id: dd4218eb-9237-4611-ba2f-1781391cadd1
    :setup: standalone gssapi instance
    :steps:
        1. Invalidate a sasl map
        2. Attempt to bind
    :expectedresults:
        1. The sasl map is invalid.
        2. The bind fails.
    """
    saslmaps = SaslMappings(topology_st_gssapi.standalone)
    saslmap = saslmaps.get('suffix map')
    saslmap.set('nsSaslMapFilterTemplate', '(invalidattr=\\1)')
    with pytest.raises(ldap.INVALID_CREDENTIALS):
        conn = testuser.bind_gssapi()
    saslmap.set('nsSaslMapFilterTemplate', '(uid=\\1)')