To find the lower bound build of a requested commit position, the builds are capped at 500 below the requested build.

https://findit-for-me.appspot.com/waterfall/flake?key=ag9zfmZpbmRpdC1mb3ItbWVyrgELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCJ4Y2hyb21pdW0ud2luL1dpbjEwIFRlc3RzIHg2NC8yMjcwMS9jcm9uZXRfdW5pdHRlc3RzIG9uIFdpbmRvd3MtMTAtMTUwNjMvVTNSaGJHVkliM04wVW1WemIyeDJaWEpVWlhOMExsTjBZV3hsVlhOaFltbHNhWFI1DAsSE01hc3RlckZsYWtlQW5hbHlzaXMYAQw

Generator pipelines.flake_failure.next_commit_position_pipeline.NextCommitPositionPipeline(*(u'ENCODED:boHH6HlAZEbA0jDg7NHrcEFIN',), **{'analysis_urlsafe_key': u'ag9zfmZpbmRpdC1mb3ItbWVyrgELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCJ4Y2hyb21pdW0ud2luL1dpbjEwIFRlc3RzIHg2NC8yMjcwMS9jcm9uZXRfdW5pdHRlc3RzIG9uIFdpbmRvd3MtMTAtMTUwNjMvVTNSaGJHVkliM... (349 bytes))#38737b621fc74061be9abd6edb1852be raised exception. AssertionError:  (/base/data/home/apps/s~findit-for-me/waterfall-backend:15056-35ba78c.409142294549913140/infra_api_clients/../third_party/pipeline/pipeline.py:2434)
Traceback (most recent call last):
  File "/base/data/home/apps/s~findit-for-me/waterfall-backend:15056-35ba78c.409142294549913140/infra_api_clients/../third_party/pipeline/pipeline.py", line 2158, in evaluate
    self, pipeline_key, root_pipeline_key, caller_output)
  File "/base/data/home/apps/s~findit-for-me/waterfall-backend:15056-35ba78c.409142294549913140/infra_api_clients/../third_party/pipeline/pipeline.py", line 1113, in _run_internal
    return self.run(*self.args, **self.kwargs)
  File "/base/data/home/apps/s~findit-for-me/waterfall-backend:15056-35ba78c.409142294549913140/gae_libs/pipelines.py", line 262, in run
    result = self.RunImpl(arg)
  File "/base/data/home/apps/s~findit-for-me/waterfall-backend:15056-35ba78c.409142294549913140/pipelines/flake_failure/next_commit_position_pipeline.py", line 105, in RunImpl
    analysis, build_range, calculated_next_commit_position))
  File "/base/data/home/apps/s~findit-for-me/waterfall-backend:15056-35ba78c.409142294549913140/services/flake_failure/next_commit_position_utils.py", line 49, in GetNextCommitPositionFromBuildRange
    requested_commit_position <= build_range.upper)
AssertionError

In this case, this is also a long-standing flake, and instead FA should bail out of analysis, rather than attempt to go back further in time