This test failure looks like flake to me.

https://luci-milo.appspot.com/buildbot/chromeos/gale-paladin/3486

INFO	----	----	kernel=3.18.0-15954-g462cc908d909	localtime=Aug 10 08:09:17	timestamp=1502377757	
START	----	----	timestamp=1501309178	localtime=Jul 28 23:19:38	
	START	jetstream_GuestInterfaces	jetstream_GuestInterfaces	timestamp=1501309179	localtime=Jul 28 23:19:39	
		ERROR	jetstream_GuestInterfaces	jetstream_GuestInterfaces	timestamp=1501309347	localtime=Jul 28 23:22:27	Command <ap-configure --ssid="test_ssid" --wpa2_psk="test_psk" --guest_network=1 --guest_network_ssid="guest_ssid" --guest_network_psk="guest_psk"> failed, rc=-6, Command returned non-zero exit status
	END ERROR	jetstream_GuestInterfaces	jetstream_GuestInterfaces	timestamp=1501309347	localtime=Jul 28 23:22:27	
END GOOD	----	----	timestamp=1501309351	localtime=Jul 28 23:22:31	
INFO	----	----	timestamp=1502378003	localtime=Aug 10 08:13:23	Start crashcollection record
INFO	----	New Crash Dump	timestamp=1502378003	localtime=Aug 10 08:13:23	/usr/local/autotest/results/134173173-chromeos-test/chromeos6-row21-jetstream-host3/sysinfo/var/spool/crash/ap_controller.20170729.061708.16860.dmp
INFO	----	New Crash Dump	timestamp=1502378003	localtime=Aug 10 08:13:23	/usr/local/autotest/results/134173173-chromeos-test/chromeos6-row21-jetstream-host3/jetstream_GuestInterfaces/sysinfo/iteration.1/var/spool/crash/ap_controller.20170729.062017.18786.dmp
INFO	----	New Crash Dump	timestamp=1502378003	localtime=Aug 10 08:13:23	/usr/local/autotest/results/134173173-chromeos-test/chromeos6-row21-jetstream-host3/jetstream_GuestInterfaces/sysinfo/iteration.1/var/spool/crash/ap_configure.20170729.062017.18901.dmp
INFO	----	New Crash Dump	timestamp=1502378003	localtime=Aug 10 08:13:23	/usr/local/autotest/results/134173173-chromeos-test/chromeos6-row21-jetstream-host3/jetstream_GuestInterfaces/sysinfo/iteration.1/var/spool/crash/ap_controller.20170729.061956.18369.dmp
INFO	----	----	timestamp=1502378003	localtime=Aug 10 08:13:23	End crashcollection record