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-144/2018-11-13-0115/flakey.log

The failure seems to be in the "samba-ad-dc-2" suite, whose build logs are available here:

   https://git.samba.org/autobuild.flakey.sn-devel-144/2018-11-13-0115/samba-ad-dc-2.stderr
   https://git.samba.org/autobuild.flakey.sn-devel-144/2018-11-13-0115/samba-ad-dc-2.stdout
  
The top commit at the time of the failure was:

commit 751c0cc7c4482b0546329b9aac49e76b529f0302
Author: Volker Lendecke <vl at samba.org>
Date:   Mon Nov 12 16:21:55 2018 +0100

    winbindd: Fix crash when taking profiles
    
    Bug: https://bugzilla.samba.org/show_bug.cgi?id=13629
    Signed-off-by: Volker Lendecke <vl at samba.org>
    Reviewed-by: Björn Baumbach <bbaumbach at samba.org>
    
    Autobuild-User(master): Volker Lendecke <vl at samba.org>
    Autobuild-Date(master): Mon Nov 12 20:20:52 CET 2018 on sn-devel-144

and the last 50 lines of the stdout log were:

[109(1077)/147 at 31m49s] samba4.ldap.acl.python(fl2000dc)(fl2000dc)
[110(1130)/147 at 35m14s] samba4.ldap.login_basics.python(offlinebackupdc)(offlinebackupdc)
[111(1132)/147 at 35m23s] samba4.ldap.login_basics.python(restoredc)(restoredc)
[112(1134)/147 at 35m33s] samba4.ldap.login_basics.python(renamedc)(renamedc)
[113(1136)/147 at 35m42s] samba4.ldap.login_basics.python(labdc)(labdc)
[114(1138)/147 at 35m52s] samba.tests.posixacl(ad_dc_no_nss:local)
[115(1207)/147 at 37m36s] samba4.rpc.echo(offlinebackupdc)
[116(1217)/147 at 37m40s] samba4.rpc.echo(offlinebackupdc:local)
[117(1227)/147 at 37m45s] samba4.rpc.echo.testallowed(offlinebackupdc:local)
[118(1237)/147 at 37m49s] samba4.rpc.echo.testdenied(offlinebackupdc:local)
[119(1247)/147 at 37m53s] samba4.blackbox.smbclient(offlinebackupdc:local)(offlinebackupdc:local)
[120(1249)/147 at 37m55s] samba4.rpc.echo(restoredc)
[121(1259)/147 at 38m0s] samba4.rpc.echo(restoredc:local)
[122(1269)/147 at 38m4s] samba4.rpc.echo.testallowed(restoredc:local)
[123(1279)/147 at 38m8s] samba4.rpc.echo.testdenied(restoredc:local)
[124(1289)/147 at 38m12s] samba4.blackbox.smbclient(restoredc:local)(restoredc:local)
[125(1291)/147 at 38m15s] samba4.rpc.echo(renamedc)
[126(1301)/147 at 38m19s] samba4.rpc.echo(renamedc:local)
[127(1311)/147 at 38m24s] samba4.rpc.echo.testallowed(renamedc:local)
[128(1321)/147 at 38m28s] samba4.rpc.echo.testdenied(renamedc:local)
[129(1331)/147 at 38m31s] samba4.blackbox.smbclient(renamedc:local)(renamedc:local)
[130(1333)/147 at 38m33s] samba4.rpc.echo(labdc)
[131(1343)/147 at 38m37s] samba4.rpc.echo(labdc:local)
[132(1353)/147 at 38m42s] samba4.rpc.echo.testallowed(labdc:local)
[133(1363)/147 at 38m43s] samba4.rpc.echo.testdenied(labdc:local)
[134(1373)/147 at 38m43s] samba4.blackbox.smbclient(labdc:local)(labdc:local)
[135(1375)/147 at 38m45s] samba4.drs.repl_schema.python(vampire_2000_dc)(vampire_2000_dc)
[136(1384)/147 at 41m59s] samba.tests.blackbox.samba_dnsupdate(chgdcpass:local)
UNEXPECTED(failure): samba.tests.blackbox.samba_dnsupdate.samba.tests.blackbox.samba_dnsupdate.SambaDnsUpdateTests.test_samba_dnsupate_no_change(chgdcpass:local)
REASON: Exception: Exception: Traceback (most recent call last):
  File "bin/python/samba/tests/blackbox/samba_dnsupdate.py", line 46, in test_samba_dnsupate_no_change
    self.assertTrue("No DNS updates needed" in out, out)
AssertionError: IPs: ['fd00::5357:5f20'

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
samba.tests.samba_tool.dnscmd(chgdcpass:local) -> 528
samba4.ldap.secdesc.python(fl2000dc)(fl2000dc) -> 294
samba4.ldap.acl.python(fl2000dc)(fl2000dc) -> 205
samba4.drs.repl_schema.python(vampire_2000_dc)(vampire_2000_dc) -> 122
samba4.blackbox.join_ldapcmp(restoredc) -> 59
samba4.blackbox.join_ldapcmp(renamedc) -> 59
samba4.ldap_schema.python(fl2000dc)(fl2000dc) -> 59
samba4.blackbox.join_ldapcmp(backupfromdc) -> 59
samba.tests.dcerpc.raw_protocol(chgdcpass) -> 56
samba4.blackbox.join_ldapcmp(offlinebackupdc) -> 55
ERROR: test failed with exit code 1