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-144/2018-04-07-0628/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-144/2018-04-07-0628/samba-ad-dc-2.stderr
   https://git.samba.org/autobuild.flakey.sn-devel-144/2018-04-07-0628/samba-ad-dc-2.stdout
  
The top commit at the time of the failure was:

commit 5bba8c393d78235111cc5d744bb393847ca16283
Author: Ralph Wuerthner <ralph.wuerthner at de.ibm.com>
Date:   Thu Mar 29 10:00:41 2018 +0200

    s3:smb2_tcon: Add check to prevent non-DFS clients from connecting to an msdfs proxy.
    
    Signed-off-by: Ralph Wuerthner <ralph.wuerthner at de.ibm.com>
    Reviewed-by: David Disseldorp <ddiss at samba.org>
    Reviewed-by: Jeremy Allison <jra at samba.org>
    
    Autobuild-User(master): Jeremy Allison <jra at samba.org>
    Autobuild-Date(master): Sat Apr  7 05:05:22 CEST 2018 on sn-devel-144

and the last 50 lines of the stdout log were:

[70(519)/99 at 2m0s] samba.wbinfo_simple.change-secret.domain=$DOMAIN(chgdcpass:local)
[71(520)/99 at 2m0s] samba.wbinfo_simple.check-secret.domain=$DOMAIN(chgdcpass:local)
[72(521)/99 at 2m0s] samba.wbinfo_simple.online-status.domain=$DOMAIN(chgdcpass:local)
[73(522)/99 at 2m1s] samba.wbinfo_simple.domain-users(chgdcpass:local)
[74(523)/99 at 2m1s] samba.wbinfo_simple.domain-groups(chgdcpass:local)
[75(524)/99 at 2m1s] samba.wbinfo_simple.name-to-sid=$DC_USERNAME(chgdcpass:local)
[76(525)/99 at 2m1s] samba.wbinfo_simple.name-to-sid=$DOMAIN/$DC_USERNAME(chgdcpass:local)
[77(526)/99 at 2m1s] samba.wbinfo_simple.user-info=$DOMAIN/$DC_USERNAME(chgdcpass:local)
[78(527)/99 at 2m2s] samba.wbinfo_simple.user-groups=$DOMAIN/$DC_USERNAME(chgdcpass:local)
[79(528)/99 at 2m2s] samba.wbinfo_simple.authenticate=$DOMAIN/$DC_USERNAME%$DC_PASSWORD(chgdcpass:local)
[80(529)/99 at 2m2s] samba.wbinfo_simple.allocate-uid(chgdcpass:local)
[81(530)/99 at 2m2s] samba.wbinfo_simple.allocate-gid(chgdcpass:local)
[82(531)/99 at 2m2s] samba.wbinfo_sids2xids.(chgdcpass:local)(chgdcpass:local)
[83(532)/99 at 2m23s] samba.ntlm_auth.diagnostics(chgdcpass:local)(chgdcpass:local)
[84(533)/99 at 2m23s] samba.ntlm_auth.(chgdcpass:local)(chgdcpass:local)
[85(552)/99 at 2m27s] samba.tests.samba_tool.fsmo(fl2000dc:local)
[86(553)/99 at 2m28s] samba.tests.samba_tool.edit(fl2000dc:local)
[87(556)/99 at 2m30s] samba.tests.samba_tool.user_check_password_script(chgdcpass:local)
[88(557)/99 at 2m33s] samba.tests.samba_tool.sites(chgdcpass:local)
[89(560)/99 at 2m37s] samba.tests.samba_tool.dnscmd(chgdcpass:local)
[90(574)/99 at 6m15s] samba.tests.dcerpc.raw_protocol(chgdcpass)
[91(692)/99 at 7m1s] samba.tests.encrypted_secrets(fl2000dc:local)
[92(694)/99 at 7m1s] samba4.ldap_schema.python(fl2000dc)(fl2000dc)
[93(720)/99 at 7m24s] samba4.ldap.possibleInferiors.python(fl2000dc)(fl2000dc)
[94(962)/99 at 7m25s] samba4.ldap.secdesc.python(fl2000dc)(fl2000dc)
[95(1045)/99 at 8m58s] samba4.ldap.acl.python(fl2000dc)(fl2000dc)
[96(1097)/99 at 9m58s] samba4.drs.repl_schema.python(vampire_2000_dc)(vampire_2000_dc)
[97(1106)/99 at 11m18s] 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 41, 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) -> 217
samba4.ldap.secdesc.python(fl2000dc)(fl2000dc) -> 92
samba4.ldap.acl.python(fl2000dc)(fl2000dc) -> 61
samba4.drs.repl_schema.python(vampire_2000_dc)(vampire_2000_dc) -> 47
samba.tests.dcerpc.raw_protocol(chgdcpass) -> 46
samba4.ldap_schema.python(fl2000dc)(fl2000dc) -> 23
samba.wbinfo_sids2xids.(chgdcpass:local)(chgdcpass:local) -> 21
samba4.blackbox.kinit(fl2000dc:local)(fl2000dc:local) -> 13
samba4.net.api.become.dc(fl2000dc) -> 10
samba4.blackbox.chgdcpass(chgdcpass) -> 6
ERROR: test failed with exit code 1