First failing builds:

https://ci.chromium.org/buildbot/chromium.gpu.fyi/Win7%20Experimental%20Release%20%28NVIDIA%29/2828
https://ci.chromium.org/buildbot/chromium.gpu.fyi/Win7%20x64%20dEQP%20Release%20%28NVIDIA%29/8410

Exception:


Traceback (most recent call last):
  File "E:\b\rr\tmphnfftx\rw\checkout\scripts\slave\.recipe_deps\recipe_engine\recipe_engine\run.py", line 275, in _new_run
    recipe_result = recipe_script.run(api, self.properties, self.environ)
  File "E:\b\rr\tmphnfftx\rw\checkout\scripts\slave\.recipe_deps\recipe_engine\recipe_engine\loader.py", line 98, in run
    self.run_steps, properties, environ, self.PROPERTIES, api=api)
  File "E:\b\rr\tmphnfftx\rw\checkout\scripts\slave\.recipe_deps\recipe_engine\recipe_engine\loader.py", line 626, in invoke_with_properties
    arg_names, **additional_args)
  File "E:\b\rr\tmphnfftx\rw\checkout\scripts\slave\.recipe_deps\recipe_engine\recipe_engine\loader.py", line 589, in _invoke_with_properties
    return callable_obj(*props, **additional_args)
  File "E:\b\rr\tmphnfftx\rw\checkout\scripts/slave\recipes\chromium.py", line 50, in RunSteps
    api.chromium_tests.main_waterfall_steps()
  File "E:\b\rr\tmphnfftx\rw\checkout\scripts\slave\.recipe_deps\recipe_engine\recipe_engine\recipe_api.py", line 750, in _inner
    return func(*a, **kw)
  File "E:\b\rr\tmphnfftx\rw\checkout\scripts/slave\recipe_modules\chromium_tests\api.py", line 840, in main_waterfall_steps
    update_step, bot_db = self.prepare_checkout(bot_config)
  File "E:\b\rr\tmphnfftx\rw\checkout\scripts\slave\.recipe_deps\recipe_engine\recipe_engine\recipe_api.py", line 750, in _inner
    return func(*a, **kw)
  File "E:\b\rr\tmphnfftx\rw\checkout\scripts/slave\recipe_modules\chromium_tests\api.py", line 202, in prepare_checkout
    bot_config, root_solution_revision, disable_syntax_validation)
  File "E:\b\rr\tmphnfftx\rw\checkout\scripts\slave\.recipe_deps\recipe_engine\recipe_engine\recipe_api.py", line 750, in _inner
    return func(*a, **kw)
  File "E:\b\rr\tmphnfftx\rw\checkout\scripts/slave\recipe_modules\chromium_checkout\api.py", line 79, in ensure_checkout
    disable_syntax_validation=disable_syntax_validation)
  File "E:\b\rr\tmphnfftx\rw\checkout\scripts\slave\.recipe_deps\recipe_engine\recipe_engine\recipe_api.py", line 750, in _inner
    return func(*a, **kw)
  File "E:\b\rr\tmphnfftx\rw\checkout\scripts\slave\.recipe_deps\depot_tools\recipes\recipe_modules\bot_update\api.py", line 334, in ensure_checkout
    co_root = result['root']
KeyError: 'root'

Seems like an infra bug. CC'ing troopers.