autobuild[sn-devel-144]: intermittent test failure detected

[autobuild]

The autobuild test system (on sn-devel-144) has detected an intermittent failing test in 
the current master tree.

The autobuild log of the failure is available here:

   https://git.samba.org/autobuild.flakey.sn-devel-144/2019-03-31-0058/flakey.log

The failure seems to be in the "samba-ad-dc-6" suite, whose build logs are available here:

   https://git.samba.org/autobuild.flakey.sn-devel-144/2019-03-31-0058/samba-ad-dc-6.stderr
   https://git.samba.org/autobuild.flakey.sn-devel-144/2019-03-31-0058/samba-ad-dc-6.stdout
  
The top commit at the time of the failure was:

commit a2b1970a37836e46d6c9eb6bda9bd20185de96ce
Author: Garming Sam <garming at catalyst.net.nz>
Date:   Wed Mar 13 10:52:19 2019 +1300

    acl_read: Fix regression caused by db15fcfa899e1fe4d6994f68ceb299921b8aa6f1 for empty lists
    
    The original code never dereferenced attrs and only added "*" if attrs
    was NULL (not if attrs[0] was NULL).
    
    This causes significant performance issues with the new paged_results
    module introduced for 4.10 as the initial GUID search requests no
    attributes. This GUID search turns into a search for "*" and ends up
    allocating memory for the entire database.
    
    This never appears to cause changes in the final result set, only
    intermediate processing.
    
    BUG: https://bugzilla.samba.org/show_bug.cgi?id=13836
    
    Signed-off-by: Garming Sam <garming at catalyst.net.nz>
    Reviewed-by: Andrew Bartlett <abartlet at samba.org>
    
    Autobuild-User(master): Andrew Bartlett <abartlet at samba.org>
    Autobuild-Date(master): Fri Mar 29 18:37:29 UTC 2019 on sn-devel-144

and the last 50 lines of the stdout log were:

Failed to connect to 'ldap://localdc' with backend 'ldap': LDAP client internal error: NT_STATUS_ACCOUNT_LOCKED_OUT
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
badPwdCount = '3'
lockoutTime = '131984638775445570'
badPasswordTime = '131984638775445570'
logonCount = '4'
lastLogon = '131984638739177220'
lastLogonTimestamp = '131984638646741900'
userAccountControl = '512'
msDS-User-Account-Control-Computed = '16'
Failed to get kerberos credentials (kerberos required): kinit for lockout1krb5 at SAMBA.EXAMPLE.COM failed (Clients credentials have been revoked)

Account locked out: kinit for lockout1krb5 at SAMBA.EXAMPLE.COM failed (Clients credentials have been revoked)

gensec_spnego_create_negTokenInit_step: gssapi_krb5: creating NEG_TOKEN_INIT for ldap/localdc failed (next[(null)]): NT_STATUS_ACCOUNT_LOCKED_OUT
Failed to bind - LDAP client internal error: NT_STATUS_ACCOUNT_LOCKED_OUT
Failed to connect to 'ldap://localdc' with backend 'ldap': LDAP client internal error: NT_STATUS_ACCOUNT_LOCKED_OUT
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
badPwdCount = '3'
lockoutTime = '131984638775445570'
badPasswordTime = '131984638775445570'
logonCount = '4'
lastLogon = '131984638739177220'
lastLogonTimestamp = '131984638646741900'
userAccountControl = '512'
msDS-User-Account-Control-Computed = '16'
UNEXPECTED(failure): samba4.ldap.password_lockout.python(ad_dc_slowtests).__main__.PasswordTestsWithSleep.test_login_lockout_krb5(ad_dc_slowtests)
REASON: Exception: Exception: Traceback (most recent call last):
  File "/memdisk/autobuild/fl/b907189/samba-ad-dc-6/source4/dsdb/tests/python/password_lockout.py", line 1163, in test_login_lockout_krb5
    self._test_login_lockout(self.lockout1krb5_creds)
  File "/memdisk/autobuild/fl/b907189/samba-ad-dc-6/source4/dsdb/tests/python/password_lockout_base.py", line 549, in _test_login_lockout
    self.fail()
AssertionError: None

FAILED (1 failures, 0 errors and 0 unexpected successes in 0 testsuites)

A summary with detailed information can be found in:
  ./bin/ab/summary
TOP 10 slowest tests
samba4.ldap.confidential_attr.python(ad_dc_slowtests)(ad_dc_slowtests) -> 611
samba4.ldap.vlv.python(ad_dc_slowtests)(ad_dc_slowtests) -> 530
samba4.rpc.samr.passwords.lockout on ncacn_np with (ad_dc_slowtests) -> 231
samba4.rpc.samr.passwords.pwdlastset on ncacn_np with (ad_dc_slowtests) -> 202
samba4.rpc.samlogon on ncacn_np with (ad_dc_slowtests) -> 55
samba4.rpc.samr.passwords.badpwdcount on ncacn_np with (ad_dc_slowtests) -> 20
samba4.rpc.samr.passwords on ncacn_np with (ad_dc_slowtests) -> 17
samba4.rpc.samr.large-dc on ncacn_np with (ad_dc_slowtests) -> 11
samba4.rpc.samr.users on ncacn_np with (ad_dc_slowtests) -> 6
samba4.rpc.samr.users.privileges on ncacn_np with (ad_dc_slowtests) -> 3
ERROR: test failed with exit code 1