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-144/2018-05-22-1336/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-144/2018-05-22-1336/samba.stderr
   https://git.samba.org/autobuild.flakey.sn-devel-144/2018-05-22-1336/samba.stdout
  
The top commit at the time of the failure was:

commit 20fda4f600c46e73571709f718c78017b9b037a2
Author: Andrew Bartlett <abartlet at samba.org>
Date:   Mon May 21 13:58:12 2018 +1200

    auth: Use DBGC_AUTH as DBGC_CLASS for AD DC auth session code.
    
    Signed-off-by: Andrew Bartlett <abartlet at samba.org>
    Reviewed-by: Jeremy Allison <jra at samba.org>
    
    Autobuild-User(master): Jeremy Allison <jra at samba.org>
    Autobuild-Date(master): Tue May 22 02:42:32 CEST 2018 on sn-devel-144

and the last 50 lines of the stdout log were:

[755(4049)/853 at 48m45s] samba.tests.blackbox.traffic_replay(ad_dc_ntvfs)
[756(4055)/853 at 48m55s] samba.tests.blackbox.traffic_learner(ad_dc_ntvfs)
[757(4057)/853 at 48m56s] samba.tests.blackbox.traffic_summary(ad_dc_ntvfs)
[758(4057)/853 at 48m56s] samba.tests.blackbox.smbcontrol(ad_dc_ntvfs:local)
[759(4059)/853 at 48m58s] samba.tests.blackbox.smbcontrol(promoted_dc:local)
[760(4061)/853 at 48m59s] samba4.ldap.python(ad_dc_ntvfs)(ad_dc_ntvfs)
[761(4100)/853 at 49m10s] samba4.tokengroups.krb5.python(ad_dc_ntvfs)(ad_dc_ntvfs:local)
[762(4110)/853 at 49m19s] samba4.tokengroups.ntlm.python(ad_dc_ntvfs)(ad_dc_ntvfs:local)
[763(4119)/853 at 49m27s] samba4.sam.python(ad_dc_ntvfs)(ad_dc_ntvfs)
[764(4136)/853 at 49m30s] samba4.user_account_control.python(ad_dc_ntvfs)(ad_dc_ntvfs)
[765(4147)/853 at 49m44s] samba4.schemaInfo.python(ad_dc_ntvfs)(ad_dc_ntvfs)
[766(4149)/853 at 49m46s] samba.tests.dsdb_schema_attributes(ad_dc_ntvfs:local)
[767(4154)/853 at 50m0s] samba4.urgent_replication.python(ad_dc_ntvfs)(ad_dc_ntvfs:local)
[768(4162)/853 at 50m3s] samba4.ldap.dirsync.python(ad_dc_ntvfs)(ad_dc_ntvfs)
[769(4186)/853 at 51m35s] samba4.ldap.match_rules.python(ad_dc_ntvfs)
[770(4220)/853 at 52m2s] samba4.ldap.notification.python(ad_dc_ntvfs)(ad_dc_ntvfs)
[771(4223)/853 at 52m12s] samba4.ldap.sites.python(ad_dc_ntvfs)(ad_dc_ntvfs)
[772(4234)/853 at 52m19s] samba4.ldap.sort.python(ad_dc_ntvfs)(ad_dc_ntvfs)
[773(4241)/853 at 52m28s] samba4.ldap.vlv.python(ad_dc_ntvfs)(ad_dc_ntvfs)
[774(4256)/853 at 1h4m4s] samba4.ldap.linked_attributes.python(ad_dc_ntvfs)(ad_dc_ntvfs:local)
[775(4276)/853 at 1h4m10s] samba4.ldap.rodc.python(rodc)(rodc)
[776(4282)/853 at 1h4m14s] samba4.ldap.rodc_rwdc.python(rodc)(rodc:local)
[777(4302)/853 at 1h11m25s] samba4.drs.replica_sync_rodc.python(rodc)(rodc:local)
[778(4304)/853 at 1h11m34s] samba4.ldap.password_settings.python(ad_dc_ntvfs)
[779(4314)/853 at 1h11m41s] samba4.ldap_schema.python(ad_dc_ntvfs)(ad_dc_ntvfs)
GSS client Update(krb5)(1) Update failed:  Miscellaneous failure (see text): Clock skew too great
UNEXPECTED(error): samba4.ldap_schema.python(ad_dc_ntvfs).__main__.SchemaTests.test_generated_mAPIID(ad_dc_ntvfs)
REASON: Exception: Exception: Traceback (most recent call last):
  File "/memdisk/autobuild/fl/b1698646/samba/source4/dsdb/tests/python/ldap_schema.py", line 1173, in test_generated_mAPIID
    self.ldb.modify_ldif(ldif)
  File "bin/python/samba/__init__.py", line 241, in modify_ldif
    self.modify(msg, controls)
LdbError: (3, 'ldb_wait from (null) with LDB_WAIT_ALL: Time limit exceeded (3)')

FAILED (0 failures, 1 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.vlv.python(ad_dc_ntvfs)(ad_dc_ntvfs) -> 696
samba4.ldap.rodc_rwdc.python(rodc)(rodc:local) -> 431
samba4.rpc.samr.passwords.lockout on ncacn_np with (ad_dc_ntvfs) -> 225
samba4.rpc.samr.passwords.pwdlastset on ncacn_np with (ad_dc_ntvfs) -> 199
samba3.smbtorture_s3.vfs_aio_fork(simpleserver).RW2(simpleserver) -> 137
samba4.raw.notify(ad_dc_ntvfs) -> 106
samba4.ldb.ldaps with options -U"$USERNAME%$PASSWORD"(ad_dc_ntvfs)(ad_dc_ntvfs) -> 101
samba4.ldap.dirsync.python(ad_dc_ntvfs)(ad_dc_ntvfs) -> 92
samba4.rpc.samlogon on ncacn_np with (ad_dc_ntvfs) -> 74
samba.tests.emulate.traffic_packet(ad_dc_ntvfs) -> 69
ERROR: test failed with exit code 1