It would seem this wget needs to be replaced with curl
https://cs.corp.google.com/chromeos_internal/src/platform/dev/stateful_update?rcl=0df48a149e72b77d734625aec4ff816bcbee043a&l=44

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform/dev-util/+/431d3aca8bccc38d2affebc1d8c975b2c2db16d5

commit 431d3aca8bccc38d2affebc1d8c975b2c2db16d5
Author: Keith Haddow <haddowk@chromium.org>
Date: Thu Nov 16 06:37:47 2017

[platform] Move the stateful update from wget to curl

wget is removed from the rootfs  crbug.com/781538  change the
stateful update to use curl rather than wget

BUG= chromium:785487 
TEST=ran unittests, will run trybot job before submit.

Change-Id: I0afc1b3e3f9520cc20f8ff65d38712b4957e010b
Reviewed-on: https://chromium-review.googlesource.com/773114
Commit-Ready: Keith Haddow <haddowk@chromium.org>
Tested-by: Keith Haddow <haddowk@chromium.org>
Reviewed-by: David Riley <davidriley@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>

[modify] https://crrev.com/431d3aca8bccc38d2affebc1d8c975b2c2db16d5/stateful_update

Hooray! This change also fixes  bug 622129 .

This fix did not completely fix the builders - we had to change some infra configuration as well https://chrome-internal-review.googlesource.com/#/c/chromeos/chromeos-admin/+/509975/

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform/dev-util/+/06b343621d7249ab20e7f88fae453e6ec04bdd81

commit 06b343621d7249ab20e7f88fae453e6ec04bdd81
Author: Keith Haddow <haddowk@chromium.org>
Date: Sat Feb 03 00:24:42 2018

[platform] Move the stateful update from wget to curl

wget is removed from the rootfs  crbug.com/781538  change the
stateful update to use curl rather than wget

BUG= chromium:785487 
TEST=ran unittests, will run trybot job before submit.

Change-Id: I0afc1b3e3f9520cc20f8ff65d38712b4957e010b
Reviewed-on: https://chromium-review.googlesource.com/773114
Commit-Ready: Keith Haddow <haddowk@chromium.org>
Tested-by: Keith Haddow <haddowk@chromium.org>
Reviewed-by: David Riley <davidriley@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
(cherry picked from commit 431d3aca8bccc38d2affebc1d8c975b2c2db16d5)
Reviewed-on: https://chromium-review.googlesource.com/900265
Reviewed-by: Keith Haddow <haddowk@chromium.org>
Commit-Queue: Keith Haddow <haddowk@chromium.org>
Trybot-Ready: Keith Haddow <haddowk@chromium.org>

[modify] https://crrev.com/06b343621d7249ab20e7f88fae453e6ec04bdd81/stateful_update

Keith,
You didn't actually fix the root cause with this change.
I'm seeing the same issue on whirlwind-test-ap updates (and it's been an issue for a long time but no one looked.) See crbug.com/808288.

wget is available on the offending machine (in /usr/local/bin) BUT I don't understand why the "eval" use of wget is failing to find /usr/local/bin $PATH.  By modifying the script to use /usr/local/bin/wget, it seems to work fine. Using "curl" doesn't change the underlying issue.  Maybe someone else knows why $PATH isn't getting set when stateful_update is run.

However, I'm also re-opening this bug since the gmerge ebuild RDEPENDS on wget, not on curl. Since "no good deed goes unpunished", can you please:

1) update the gmerge ebuild to RDEPEND on curl?
2) determine if nothing else in gmerge package is using wget? (ie consider removing RDEPEND on wget)

$ equery-whirlwind b stateful_update
 * Searching for stateful_update ... 
chromeos-base/gmerge-0.0.1-r1085 (/usr/local/bin/stateful_update)

$ equery-whirlwind w chromeos-base/gmerge
/mnt/host/source/src/third_party/chromiumos-overlay/chromeos-base/gmerge/gmerge-0.0.1-r1088.ebuild

RDEPEND="app-shells/bash
        dev-lang/python
        dev-util/shflags
        net-misc/wget
        sys-apps/portage"
DEPEND="${RDEPEND}"


$ equery-whirlwind b curl
 * Searching for curl ... 
net-misc/curl-7.57.0 (/usr/include/curl)
net-misc/curl-7.57.0 (/usr/bin/curl)

wget used to be installed in the rootfs.  we changed it to only be in the dev/test images.  curl on the other hand is in the rootfs.  so changing things to use curl instead of wget is fine.

Ok. Then just need to fix the RDEPENDS. I'll upload a CL for that if Keith doesn't object.

My goal was primarily to make Keith aware the ebuilds specify runtime dependencies. Trying to use features/embedded has made me much more sensitive to that.

No objection, I will keep a look out for RDEPENDS in the future.

Excellent! I've uploaded:

https://chromium-review.googlesource.com/#/c/chromiumos/overlays/chromiumos-overlay/+/941731

gmerge: replace wget with curl in REDEPENDS 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/2337c433716aaa05a8141f5589a1c545965d50f7

commit 2337c433716aaa05a8141f5589a1c545965d50f7
Author: Grant Grundler <grundler@chromium.org>
Date: Fri Mar 02 08:11:54 2018

gmerge: replace wget with curl in REDEPENDS

https://chromium-review.googlesource.com/773114 switch from wget
to curl. Just updating the RDEPENDS to match.

BUG= chromium:785487 
TEST=no change to runtime since /usr/bin/curl is already present

Change-Id: Ie61e0f49e4acd061d4bc0829d0e2daf80f8cc3a8
Reviewed-on: https://chromium-review.googlesource.com/941731
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Grant Grundler <grundler@chromium.org>
Reviewed-by: Grant Grundler <grundler@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>

[modify] https://crrev.com/2337c433716aaa05a8141f5589a1c545965d50f7/chromeos-base/gmerge/gmerge-9999.ebuild

Looks like Grant's CL has landed marking as fixed.