also, why locales - en:None?
2020-04-11T22:40:50.397211+00:00 app[worker.1]: Retrieving changed files for: /app/media/projects/stellaris/europa-cafe/stellaris.hg/locales/en:None
2020-04-11T22:40:50.397351+00:00 app[worker.1]: [2020-04-11 22:40:50,396: INFO/ForkPoolWorker-2] Retrieving changed files for: /app/media/projects/stellaris/europa-cafe/stellaris.hg/locales/en:None
2020-04-11T22:40:51.291404+00:00 app[worker.1]: [2020-04-11 22:40:51,290: ERROR/ForkPoolWorker-2] Task pontoon.sync.tasks.sync_project[3c43a489-1ca1-4a92-94ed-981c526b6f10] raised unexpected: DoesNotExist('Locale matching query does not exist.')
2020-04-11T22:40:51.291413+00:00 app[worker.1]: Traceback (most recent call last):
2020-04-11T22:40:51.291416+00:00 app[worker.1]: File "/app/.heroku/python/lib/python3.7/site-packages/celery/app/trace.py", line 385, in trace_task
2020-04-11T22:40:51.291417+00:00 app[worker.1]: R = retval = fun(*args, **kwargs)
2020-04-11T22:40:51.291417+00:00 app[worker.1]: File "/app/.heroku/python/lib/python3.7/site-packages/newrelic/hooks/application_celery.py", line 84, in wrapper
2020-04-11T22:40:51.291418+00:00 app[worker.1]: return wrapped(*args, **kwargs)
2020-04-11T22:40:51.291418+00:00 app[worker.1]: File "/app/.heroku/python/lib/python3.7/site-packages/celery/app/trace.py", line 648, in __protected_call__
2020-04-11T22:40:51.291419+00:00 app[worker.1]: return self.run(*args, **kwargs)
2020-04-11T22:40:51.291419+00:00 app[worker.1]: File "/app/pontoon/sync/core.py", line 69, in wrapped_func
2020-04-11T22:40:51.291420+00:00 app[worker.1]: return func(self, *args, **kwargs)
2020-04-11T22:40:51.291420+00:00 app[worker.1]: File "/app/pontoon/sync/tasks.py", line 105, in sync_project
2020-04-11T22:40:51.291421+00:00 app[worker.1]: source_changes = sync_sources(db_project, now, force, no_pull)
2020-04-11T22:40:51.291421+00:00 app[worker.1]: File "/app/pontoon/sync/tasks.py", line 148, in sync_sources
2020-04-11T22:40:51.291421+00:00 app[worker.1]: db_project, now, full_scan=force
2020-04-11T22:40:51.291422+00:00 app[worker.1]: File "/app/pontoon/sync/core.py", line 33, in update_originals
2020-04-11T22:40:51.291423+00:00 app[worker.1]: db_project, vcs_project
2020-04-11T22:40:51.291423+00:00 app[worker.1]: File "/app/pontoon/sync/core.py", line 130, in update_resources
2020-04-11T22:40:51.291423+00:00 app[worker.1]: for relative_path, vcs_resource in vcs_project.resources.items():
2020-04-11T22:40:51.291424+00:00 app[worker.1]: File "/app/.heroku/python/lib/python3.7/site-packages/django/utils/functional.py", line 80, in __get__
2020-04-11T22:40:51.291424+00:00 app[worker.1]: res = instance.__dict__[self.name] = self.func(instance)
2020-04-11T22:40:51.291425+00:00 app[worker.1]: File "/app/pontoon/sync/vcs/models.py", line 378, in resources
2020-04-11T22:40:51.291425+00:00 app[worker.1]: resources[path] = VCSResource(self, path, locales=locales)
2020-04-11T22:40:51.291425+00:00 app[worker.1]: File "/app/pontoon/sync/vcs/models.py", line 639, in __init__
2020-04-11T22:40:51.291426+00:00 app[worker.1]: source_resource_path, locale=Locale.objects.get(code="en-US")
2020-04-11T22:40:51.291426+00:00 app[worker.1]: File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/manager.py", line 82, in manager_method
2020-04-11T22:40:51.291427+00:00 app[worker.1]: return getattr(self.get_queryset(), name)(*args, **kwargs)
2020-04-11T22:40:51.291427+00:00 app[worker.1]: File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/query.py", line 408, in get
2020-04-11T22:40:51.291428+00:00 app[worker.1]: self.model._meta.object_name
2020-04-11T22:40:51.291428+00:00 app[worker.1]: pontoon.base.models.Locale.DoesNotExist: Locale matching query does not exist.
this thing is https://europa-cafe.codebasehq.com/projects/europa-cafe/repositories/stellaris/raw/tip/locales/en/achievements.properties
so locales/{locale_code}/path/to/file.extension
is same.