I can reproduce easily enough:

cros tryjob -b release-R65-10323.B -g 900169 -g 902706 --swarming stumpy-test-ap-tryjob

http://cros-goldeneye/chromeos/healthmonitoring/buildDetails?buildbucketId=8955304268758348160

This makes no sense at all.

It's a pretty bad bug in the new swarming recipe's configuration handling.

I just don't understand how this was missed in testing. Adding many more test cases.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/tools/build/+/6ead2e309fae1836f3abfe4db756a5d0bb4d2510

commit 6ead2e309fae1836f3abfe4db756a5d0bb4d2510
Author: Don Garrett <dgarrett@google.com>
Date: Wed Feb 07 21:19:38 2018

cros/swarming recipie.

This recipe was not being properly configured. Fix this, and add a lot
more tests to help understand this in the future.

BUG= chromium:809699 

Change-Id: I2cd414b5b79e2ee5d75f89de1abb3067ae4caf3f
Reviewed-on: https://chromium-review.googlesource.com/905629
Commit-Queue: Don Garrett <dgarrett@chromium.org>
Reviewed-by: Nodir Turakulov <nodir@chromium.org>

[modify] https://crrev.com/6ead2e309fae1836f3abfe4db756a5d0bb4d2510/scripts/slave/recipes/cros/swarming.expected/swarming_builder.json
[add] https://crrev.com/6ead2e309fae1836f3abfe4db756a5d0bb4d2510/scripts/slave/recipes/cros/swarming.expected/tryjob_simple.json
[modify] https://crrev.com/6ead2e309fae1836f3abfe4db756a5d0bb4d2510/scripts/slave/recipes/cros/swarming.py
[modify] https://crrev.com/6ead2e309fae1836f3abfe4db756a5d0bb4d2510/scripts/slave/README.recipes.md
[add] https://crrev.com/6ead2e309fae1836f3abfe4db756a5d0bb4d2510/scripts/slave/recipes/cros/swarming.expected/master_builder.json
[add] https://crrev.com/6ead2e309fae1836f3abfe4db756a5d0bb4d2510/scripts/slave/recipes/cros/swarming.expected/tryjob_complex.json
[add] https://crrev.com/6ead2e309fae1836f3abfe4db756a5d0bb4d2510/scripts/slave/recipes/cros/swarming.expected/complex_slave_builder.json

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/tools/build/+/0525bcb9930bb802fb19760bb451418a3805cf38

commit 0525bcb9930bb802fb19760bb451418a3805cf38
Author: Don Garrett <dgarrett@google.com>
Date: Wed Feb 07 22:43:37 2018

cros/swarming recipe: Remove args assert.

A new assert in the previous CL requires arguments to be in a list,
and fails incorrectly if they are in a tuple. This happens, so remove
the assert, and add a test for tuples.

BUG= chromium:809699 
TBR=nodir@chromium.org

Change-Id: Ifcaa5b86362c93db8c2e68d617347b85642bba9a
Reviewed-on: https://chromium-review.googlesource.com/907545
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Commit-Queue: Don Garrett <dgarrett@chromium.org>

[add] https://crrev.com/0525bcb9930bb802fb19760bb451418a3805cf38/scripts/slave/recipes/cros/swarming.expected/tuple_args.json
[modify] https://crrev.com/0525bcb9930bb802fb19760bb451418a3805cf38/scripts/slave/recipes/cros/swarming.py

Cmd:
  cros tryjob --swarming -g 858174 --branch release-R65-10323.B lumpy-compile-only-pre-cq

Build:
  http://cros-goldeneye/chromeos/healthmonitoring/buildDetails?buildbucketId=8955209776461890624

cbuildbot_launch:
  /b/swarming/w/ir/kitchen-workdir/chromite/scripts/cbuildbot_launch --buildroot /b/swarming/w/ir/cache/cbuild --branch master --buildbucket-id 8955209776461890624 --git-cache-dir /b/swarming/w/ir/cache/git --goma_dir /b/swarming/w/ir/cache/goma_client --goma_client_json /creds/service_accounts/service-account-goma-client.json --remote-trybot -b release-R65-10323.B -g 858174 lumpy-compile-only-pre-cq


This will work, but is awkward, since the branch is listed incorrectly then a second time correctly.

Keeping the bug until I resolve that, but lowering priority.

Further follow up, the cbuildbot command line ALSO lists branch twice. That's even weirder.

Actually, I filed https://crbug.com/810175 for follow up. Marking this fixed.

Issue 809265 has been merged into this issue.