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-144/2018-11-15-2022/flakey.log

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

   https://git.samba.org/autobuild.flakey.sn-devel-144/2018-11-15-2022/samba.stderr
   https://git.samba.org/autobuild.flakey.sn-devel-144/2018-11-15-2022/samba.stdout
  
The top commit at the time of the failure was:

commit c1dd6382e3211792e313f7d559b943f55c9cb0e1
Author: Martin Schwenke <martin at meltin.net>
Date:   Wed Nov 14 14:09:42 2018 +1100

    ctdb-tests: Make the debug hung script test cope with unreadable stacks
    
    Ideally this would just involve using "test -r".  However, operating
    system security features may mean that kernel stacks are not readable
    even though they appear to be.
    
    Instead, try reading that stack of a process on the test node.  If
    that succeeds then so should reading the stack of the "stuck" sleep
    process in the test.
    
    BUG: https://bugzilla.samba.org/show_bug.cgi?id=13684
    
    Signed-off-by: Martin Schwenke <martin at meltin.net>
    Reviewed-by: Tim Beale <timbeale at catalyst.net.nz>
    
    Autobuild-User(master): Tim Beale <timbeale at samba.org>
    Autobuild-Date(master): Thu Nov 15 08:15:32 CET 2018 on sn-devel-144

and the last 50 lines of the stdout log were:

[792(4836)/851 at 1h23m55s] samba4.rpc.echo.testdenied(rodc:local)
[793(4846)/851 at 1h23m59s] samba4.blackbox.smbclient(rodc:local)(rodc:local)
[794(4848)/851 at 1h24m0s] samba.tests.samba_tool.rodc(rodc:local)
[795(4857)/851 at 1h24m29s] samba.blackbox.rpcclient_samlogon(rodc:local)
[796(4861)/851 at 1h24m30s] samba.blackbox.rpcclient_samlogon_testallowed(rodc:local)
[797(4865)/851 at 1h24m30s] samba.blackbox.rpcclient_samlogon_testdenied(rodc:local)
[798(4869)/851 at 1h24m31s] samba4.drs.ridalloc_exop.python(vampire_dc)(vampire_dc)
[799(4880)/851 at 1h29m53s] samba4.drs.samba_tool_drs.python(vampire_dc)(vampire_dc:local)
[800(4894)/851 at 1h33m16s] samba4.drs.samba_tool_drs_showrepl.python(vampire_dc)(vampire_dc:local)
[801(4898)/851 at 1h33m29s] samba4.drs.replica_sync.python(vampire_dc)(vampire_dc:local)
[802(4914)/851 at 1h37m17s] samba4.drs.delete_object.python(vampire_dc)(vampire_dc)
[803(4916)/851 at 1h37m26s] samba4.drs.fsmo.python(vampire_dc)(vampire_dc)
[804(4921)/851 at 1h37m43s] samba4.drs.repl_move.python(vampire_dc)(vampire_dc)
[805(4942)/851 at 1h40m1s] samba4.drs.getnc_exop.python(vampire_dc)(vampire_dc)
[806(4954)/851 at 1h40m22s] samba4.drs.getnc_unpriv.python(vampire_dc)(vampire_dc)
[807(4958)/851 at 1h40m28s] samba4.drs.linked_attributes_drs.python(vampire_dc)(vampire_dc)
[808(4961)/851 at 1h40m30s] samba4.drs.link_conflicts.python(vampire_dc)(vampire_dc)
[809(4973)/851 at 1h48m8s] samba4.drs.samba_tool_drs.python(promoted_dc)(promoted_dc:local)
[810(4987)/851 at 1h51m32s] samba4.drs.samba_tool_drs_showrepl.python(promoted_dc)(promoted_dc:local)
[811(4991)/851 at 1h51m44s] samba4.drs.replica_sync.python(promoted_dc)(promoted_dc:local)
[812(5007)/851 at 1h56m43s] samba4.drs.delete_object.python(promoted_dc)(promoted_dc)
[813(5009)/851 at 1h56m52s] samba4.drs.fsmo.python(promoted_dc)(promoted_dc)
[814(5014)/851 at 1h57m9s] samba4.drs.repl_move.python(promoted_dc)(promoted_dc)
[815(5035)/851 at 1h59m4s] samba4.drs.getnc_exop.python(promoted_dc)(promoted_dc)
UNEXPECTED(failure): samba4.drs.getnc_exop.python(promoted_dc).getnc_exop.DrsReplicaSyncTestCase.test_link_utdv_hwm(promoted_dc)
REASON: Exception: Exception: Traceback (most recent call last):
  File "/memdisk/autobuild/fl/b2657786/samba/source4/torture/drs/python/getnc_exop.py", line 267, in test_link_utdv_hwm
    drsuapi.DRSUAPI_DRS_WRIT_REP)
  File "/memdisk/autobuild/fl/b2657786/samba/source4/torture/drs/python/drs_base.py", line 364, in _check_replication
    dn_ordered=dn_ordered)
  File "/memdisk/autobuild/fl/b2657786/samba/source4/torture/drs/python/drs_base.py", line 387, in _check_ctr6
    self.assertEqual(ctr6.object_count, len(expected_dns))
AssertionError: 4 != 3

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.drs.link_conflicts.python(vampire_dc)(vampire_dc) -> 458
samba4.ldap.rodc_rwdc.python(rodc)(rodc:local) -> 443
samba4.drs.ridalloc_exop.python(vampire_dc)(vampire_dc) -> 322
samba4.ldap.confidential_attr.python(ad_dc_ntvfs)(ad_dc_ntvfs) -> 314
samba4.drs.replica_sync.python(promoted_dc)(promoted_dc:local) -> 299
samba4.drs.replica_sync.python(vampire_dc)(vampire_dc:local) -> 228
samba4.ldap.vlv.python(ad_dc_ntvfs)(ad_dc_ntvfs) -> 228
samba4.rpc.samr.passwords.lockout on ncacn_np with (ad_dc_ntvfs) -> 226
samba4.drs.samba_tool_drs.python(promoted_dc)(promoted_dc:local) -> 204
samba4.drs.samba_tool_drs.python(vampire_dc)(vampire_dc:local) -> 203
ERROR: test failed with exit code 1