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:

   http://git.samba.org/autobuild.flakey.sn-devel-144/2017-03-02-1507/flakey.log

The samba build logs are available here:

   http://git.samba.org/autobuild.flakey.sn-devel-144/2017-03-02-1507/samba.stderr
   http://git.samba.org/autobuild.flakey.sn-devel-144/2017-03-02-1507/samba.stdout
  
The top commit at the time of the failure was:

commit 70923b7521786d59b76e651d566bbd61fea024cc
Author: Douglas Bagnall <douglas.bagnall at catalyst.net.nz>
Date:   Fri Feb 24 11:58:33 2017 +1300

    ndr: Use resizing array instead of linked lists (breaking ABI)
    
    The ndr token code keeps a temporary store of tokens which are
    referred to a small number of times (often once) before being
    discarded. The access patterns are somewhat stack-like, with recently
    placed tokens being accessed most often.
    
    The old code kept these tokens in a linked list, which we replace with
    a self-resizing array.
    
    This keeps everything roughly the same in big-O terms, but makes it
    all faster in practice by vastly reducing the amount of tallocing and
    pointer-chasing.
    
    The peak memory use is strictly reduced. On a 64 bit machine each core
    token struct fits in 16 bytes (after padding) while the two pointers
    used by the DLIST add another 16 bytes, so the overall list allocation
    is the same as the peak 2n array allocation -- except in the list case
    it is dwarfed by the talloc and malloc metadata overhead.
    
    Before settling on the resized arrays, we tried red-black trees, which
    are bound to be better for large ndr structures. As it happens, we
    don't deal with large structures (the size of replication clumps is
    limited to 400 objects) and the asymptotic benefits of the trees are
    not realised in practice.
    
    With luck you should find graphs comparing the performance of these
    various techniques at:
    
    https://www.samba.org/~dbagnall/perf-tests/ndr-token/
    
    This necessarily breaks the ABI because the linked list implementation
    was publicly exposed.
    
    Signed-off-by: Douglas Bagnall <douglas.bagnall at catalyst.net.nz>
    Reviewed-by: Andrew Bartlett <abartlet at samba.org>
    
    Autobuild-User(master): Andrew Bartlett <abartlet at samba.org>
    Autobuild-Date(master): Thu Mar  2 08:38:22 CET 2017 on sn-devel-144