2 Failures of this type yesterday, most recent one is in:

https://bugs.chromium.org/p/chromium/issues/detail?id=654184#c25

Looks like a failure on the client that started this:

Traceback (most recent call last):
  File "/tmp/sysinfo/autoserv-kDn3wF/bin/autotest", line 8, in <module>
    from autotest_lib.client.bin import job
  File "/tmp/sysinfo/autoserv-kDn3wF/bin/job.py", line 13, in <module>
    from autotest_lib.client.bin import utils, parallel
  File "/tmp/sysinfo/autoserv-kDn3wF/bin/utils.py", line 13, in <module>
    from autotest_lib.client.bin.base_utils import *
  File "/tmp/sysinfo/autoserv-kDn3wF/bin/base_utils.py", line 11, in <module>
    import math, re, fnmatch, logging, multiprocessing
  File "/usr/local/lib64/python2.7/multiprocessing/__init__.py", line 84, in <module>
    import _multiprocessing
ImportError: /lib64/libc.so.6: version `GLIBC_2.17' not found (required by /usr/local/lib64/python2.7/lib-dynload/_multiprocessing.so)

This lead to multiple failures afterwards:

rsync: change_dir "/tmp/sysinfo/autoserv-kDn3wF/results/default" failed: No such file or directory (2)
rsync error: some files/attrs were not transferred (see previous errors) (code 23) at main.c(1655) [Receiver=3.1.0]
...
10/25 03:23:11.621 DEBUG|        dev_server:1761| Failed to trigger auto-update process on devserver
...
RootfsUpdateError: Failed to perform rootfs update: DevServerStartupError('Devserver portfile does not exist!',)