> cat /var/log/servod_9901.log
> /proc/self/fd/9: 65: /proc/self/fd/9: slam_servov4_hub: not found

Hooboy.

That'll be a problem, yes, indeedy.

OK.  I confirmed this on chromeos6-row2-rack13-labstation2.

So...
    $ stable_version -t cros beaglebone_servo $BUILD
    Updating  Chrome OS  beaglebone_servo -> R70-10947.0.0 to R70-10923.0.0
    $ stable_version -t cros guado_labstation $BUILD
    Updating  Chrome OS  guado_labstation -> R70-10947.0.0 to R70-10923.0.0
    Unchanged Firmware   guado_labstation -> Google_Guado.6301.108.2016_10_06_1219

Things'll mostly clean up on their own now, but we'll want to check on it
in the morning.

Meantime, actually fixing the code belongs to nsanders@.

And I'm going to go re-review that CL, to find out where I went wrong.

> And I'm going to go re-review that CL, to find out where I went wrong.

The problem is straightforward:  The slam_servov4_hub function is
defined in servod_utils.sh, but that file isn't sourced in the "script"
stanza, only in the "pre-start script".

https://chromium-review.googlesource.com/c/chromiumos/third_party/hdctools/+/1168649

Observing the above issue on 

chromeos1-row2-rack10-labstation

at port 9901, 9902, 9903, 9904 (same error has been observed on all four ports)

cat /var/log/servod_9901.log
/proc/self/fd/9: 65: /proc/self/fd/9: slam_servov4_hub: not found


chromeos1-row1-rack5-labstation

at port 9901, 9902 (same error has been observed on all four ports)

cat /var/log/servod_9901.log
/proc/self/fd/9: 65: /proc/self/fd/9: slam_servov4_hub: not found

OS Version:

localhost ~ # cat /etc/lsb-release 
CHROMEOS_RELEASE_APPID={41D57E57-2150-BB76-2730-EC8AFD1D835D}
CHROMEOS_BOARD_APPID={41D57E57-2150-BB76-2730-EC8AFD1D835D}
CHROMEOS_CANARY_APPID={90F229CE-83E2-4FAF-8479-E368A34938B1}
DEVICETYPE=CHROMEBOX
CHROMEOS_RELEASE_BUILDER_PATH=guado_labstation-release/R70-10947.0.0
GOOGLE_RELEASE=10947.0.0
CHROMEOS_DEVSERVER=
CHROMEOS_RELEASE_BOARD=guado_labstation
CHROMEOS_RELEASE_BUILD_NUMBER=10947
CHROMEOS_RELEASE_BRANCH_NUMBER=0
CHROMEOS_RELEASE_CHROME_MILESTONE=70
CHROMEOS_RELEASE_PATCH_NUMBER=0
CHROMEOS_RELEASE_TRACK=testimage-channel
CHROMEOS_RELEASE_DESCRIPTION=10947.0.0 (Official Build) dev-channel guado_labstation test
CHROMEOS_RELEASE_BUILD_TYPE=Official Build
CHROMEOS_RELEASE_NAME=Chrome OS
CHROMEOS_RELEASE_VERSION=10947.0.0
CHROMEOS_AUSERVER=https://tools.google.com/service/update2

I've gone through and dealt with all of the affected labstations:
  * The labstations still running the broken build were all awaiting a
    reboot to update.  I've rebooted all of them.
  * For any labstation that looked set to update to the broken build,
    but hadn't rebooted, I've rolled it back.

There may still be a need to reboot some systems; I'm looking into it.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/hdctools/+/382fc431a82b9134c9f96b77b9d44eddd65fdc64

commit 382fc431a82b9134c9f96b77b9d44eddd65fdc64
Author: Nick Sanders <nsanders@chromium.org>
Date: Fri Aug 10 05:04:23 2018

labstation: import servod_utils

servod_utils was only imported in pre-start, but is used in pre-start
and start. So we should include it there too.

BUG= chromium:872540 
TEST=none

Change-Id: Ib97cc795021eaabd447469aa7fb9d941af320950
Reviewed-on: https://chromium-review.googlesource.com/1168649
Commit-Ready: Nick Sanders <nsanders@chromium.org>
Tested-by: Nick Sanders <nsanders@chromium.org>
Reviewed-by: Jacob Kopczynski <jkop@chromium.org>

[modify] https://crrev.com/382fc431a82b9134c9f96b77b9d44eddd65fdc64/chromeos/servod.conf

Should be fixed, over to guocb@ to verify if labstation push worked.

The servo version has been update to R70-10968.0.0 in  crbug.com/874176