All builds failed in vmtest, from the log, it seems vmtest didn't even run:
https://pantheon.corp.google.com/storage/browser/chromeos-image-archive/cyan-release/R56-9000.12.0/

more like the vm failed to start.

running a new build with clobber
https://uberchromegw.corp.google.com/i/chromeos_release/builders/cyan-release%20release-R56-9000.B/builds/11

is this the same problem as https://bugs.chromium.org/p/chromium/issues/detail?id=668418

maybe, the return code (3840) is indeed the same:

chromite.lib.cros_build_lib.TerminateRunCommandError: return code: 3840; command: /b/cbuild/shared_internal/src/platform/crostestutils/au_test_harness/cros_au_test_harness.py '--base_image=/b/cbuild/shared_internal/src/build/images/cyan/latest-cbuildbot/chromiumos_test_image.bin' '--target_image=/b/cbuild/shared_internal/src/build/images/cyan/latest-cbuildbot/chromiumos_test_image.bin' '--board=cyan' '--type=vm' '--remote=0.0.0.0' --verbose '--jobs=1' '--ssh_private_key=/b/cbuild/shared_internal/src/build/images/cyan/latest-cbuildbot/id_rsa' '--verify_suite_name=smoke' '--test_prefix=SimpleTestVerify' '--test_results_root=/b/cbuild/shared_internal/chroot/tmp/cbuildbotI0Ml58/test_harness' --no_graphics --whitelist_chrome_crashes
Received signal 15

+bhthompson

I think this might be the same issue, I guess the config update to make cyan a 'leader' propogated to the branch too, so the branch is now trying to run VMTtests but it is still allocated to a GCE builder. 

I can do a pin and restart and that will probably fix it.

The below two CLs should do it, after it finishes restarting the builders that need bare metal should have it.

https://chrome-internal-review.googlesource.com/#/c/308282/
https://chrome-internal-review.googlesource.com/#/c/308242/

The builders are now bare metal, so I am assuming this is fixed, we just need to let a build finish to verify.