rebooting build113-b4...

that didn't seem to help. twisted.log tail:

2017-03-22 16:44:40-0700 [-] sending app-level keepalive
2017-03-22 16:49:40-0700 [-] sending app-level keepalive
2017-03-22 16:54:40-0700 [-] sending app-level keepalive
2017-03-22 16:59:40-0700 [-] sending app-level keepalive
2017-03-22 17:04:40-0700 [-] sending app-level keepalive
2017-03-22 17:08:13-0700 [-] command finished with signal None, exit code 0, elapsedTime: 1712.578345
2017-03-22 17:08:13-0700 [-] SlaveBuilder.commandComplete <buildslave.commands.shell.SlaveShellCommand instance at 0x7f8bede4b050>
2017-03-22 17:08:13-0700 [Broker,client] Setting needs_reboot flag
2017-03-22 17:08:13-0700 [Broker,client] slave shutting down on command from master
2017-03-22 17:08:14-0700 [-] firing system event shutdown
2017-03-22 17:08:14-0700 [-] calling before trigger: <bound method MultiService.stopService of <twisted.application.service.MultiService instance at 0x7f8beb75d320>>
2017-03-22 17:08:14-0700 [-] stopping service <buildslave.bot.BuildSlave instance at 0x7f8beb75d368>
2017-03-22 17:08:14-0700 [-] stopping service <twisted.application.internet.TCPClient instance at 0x7f8beb75d2d8>
2017-03-22 17:08:14-0700 [-] stopped service <twisted.application.internet.TCPClient instance at 0x7f8beb75d2d8>
2017-03-22 17:08:14-0700 [-] stopping service <buildslave.bot.Bot instance at 0x7f8beb75da28>
2017-03-22 17:08:14-0700 [-] stopping service <SlaveBuilder 'android_fyi_perf_bisect' at 140238969276608>
2017-03-22 17:08:14-0700 [-] stopped service <SlaveBuilder 'android_fyi_perf_bisect' at 140238969276608>
2017-03-22 17:08:14-0700 [-] stopped service <buildslave.bot.Bot instance at 0x7f8beb75da28>
2017-03-22 17:08:14-0700 [-] stopped service <buildslave.bot.BuildSlave instance at 0x7f8beb75d368>
2017-03-22 17:08:14-0700 [-] calling during/after trigger: <bound method SelectReactor.crash of <twisted.internet.selectreactor.SelectReactor object at 0x7f8beb6b3a10>>
2017-03-22 17:08:14-0700 [-] calling during/after trigger: <bound method SelectReactor.disconnectAll of <twisted.internet.selectreactor.SelectReactor object at 0x7f8beb6b3a10>>
2017-03-22 17:08:14-0700 [Broker,client] lost remote
2017-03-22 17:08:14-0700 [Broker,client] Lost connection to master4.golo.chromium.org:8141
2017-03-22 17:08:14-0700 [Broker,client] Stopping factory <buildslave.bot.BotFactory instance at 0x7f8beb75d098>
2017-03-22 17:08:14-0700 [-] calling during/after trigger: <bound method SelectReactor._stopThreadPool of <twisted.internet.selectreactor.SelectReactor object at 0x7f8beb6b3a10>>
2017-03-22 17:08:14-0700 [-] finished firing system event
2017-03-22 17:08:14-0700 [-] Main loop terminated.
2017-03-22 17:08:14-0700 [-] Server Shut Down.

ran make restart. looks like it's picking up builds now.