The exporter is consistently failing at the first step: 'steps running steps via annotated script'

Example build:
https://uberchromegw.corp.google.com/i/chromium.infra.cron/builders/wpt-exporter/builds/16999
Stdout:
https://luci-logdog.appspot.com/v/?s=chromium%2Fbb%2Fchromium.infra.cron%2Fwpt-exporter%2F16999%2F%2B%2Frecipes%2Fstdout

@@@SEED_STEP@Uncaught Exception@@@
@@@STEP_CURSOR@Uncaught Exception@@@
@@@STEP_STARTED@@@
@@@STEP_TEXT@Uncaught Exception: KeyError('chromium',)@@@
@@@STEP_LOG_LINE@exception@Traceback (most recent call last):@@@
@@@STEP_LINK@logdog-->exception@https://luci-logdog.appspot.com/v/?s=chromium%2Fbb%2Fchromium.infra.cron%2Fwpt-exporter%2F16999%2F%2B%2Frecipes%2Fsteps%2FUncaught_Exception%2F0%2Flogs%2Fexception%2F0@@@
@@@STEP_LOG_LINE@exception@  File "/b/rr/tmpPhXAHe/rw/recipes/.recipe_deps/recipe_engine/recipe_engine/run.py", line 325, in _new_run@@@
@@@STEP_LOG_LINE@exception@    recipe_result = recipe_script.run(api, properties)@@@
@@@STEP_LOG_LINE@exception@  File "/b/rr/tmpPhXAHe/rw/recipes/.recipe_deps/recipe_engine/recipe_engine/loader.py", line 81, in run@@@
@@@STEP_LOG_LINE@exception@    self.run_steps, properties, self.PROPERTIES, api=api)@@@
@@@STEP_LOG_LINE@exception@  File "/b/rr/tmpPhXAHe/rw/recipes/.recipe_deps/recipe_engine/recipe_engine/loader.py", line 592, in invoke_with_properties@@@
@@@STEP_LOG_LINE@exception@    **additional_args)@@@
@@@STEP_LOG_LINE@exception@  File "/b/rr/tmpPhXAHe/rw/recipes/.recipe_deps/recipe_engine/recipe_engine/loader.py", line 553, in _invoke_with_properties@@@
@@@STEP_LOG_LINE@exception@    return callable_obj(*props, **additional_args)@@@
@@@STEP_LOG_LINE@exception@  File "/b/rr/tmpPhXAHe/rw/recipes/recipes/wpt_export.py", line 32, in RunSteps@@@
@@@STEP_LOG_LINE@exception@    api.gclient.set_config('chromium')@@@
@@@STEP_LOG_LINE@exception@  File "/b/rr/tmpPhXAHe/rw/recipes/.recipe_deps/recipe_engine/recipe_engine/recipe_api.py", line 794, in set_config@@@
@@@STEP_LOG_LINE@exception@    config, _ = self.make_config_params(config_name, optional, **CONFIG_VARS)@@@
@@@STEP_LOG_LINE@exception@  File "/b/rr/tmpPhXAHe/rw/recipes/.recipe_deps/recipe_engine/recipe_engine/recipe_api.py", line 775, in make_config_params@@@
@@@STEP_LOG_LINE@exception@    itm = ctx.CONFIG_ITEMS[config_name] if config_name else None@@@
@@@STEP_LOG_LINE@exception@KeyError: 'chromium'@@@