Elasticsearch::Transport::Transport::Errors::BadRequest: [400] {"error":{"root_cause":[{"type":"mapper_parsing_exception","reason":"failed to parse"}],"ty...

https://sentry.gitlab.net/gitlab/gitlabcom/issues/1024550/

Elasticsearch::Transport::Transport::Errors::BadRequest: [400] {"error":{"root_cause":[{"type":"mapper_parsing_exception","reason":"failed to parse"}],"type":"mapper_parsing_exception","reason":"failed to parse","caused_by":{"type":"illegal_argument_exception","reason":"unknown join name [snippet] for field [join_field]"}},"status":400}
  elasticsearch/transport/transport/base.rb:201:in `__raise_transport_error'
    raise error.new "[#{response.status}] #{response.body}"
  elasticsearch/transport/transport/base.rb:318:in `perform_request'
    __raise_transport_error response unless ignore.include?(response.status.to_i)
  elasticsearch/transport/transport/http/faraday.rb:20:in `perform_request'
    super do |connection, url|
  elasticsearch/transport/client.rb:131:in `perform_request'
    transport.perform_request method, path, params, body
  elasticsearch/api/actions/index.rb:100:in `index'
    perform_request(method, path, params, body).body
...
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[400] {"error":{"root_cause":[{"type":"mapper_parsing_exception","reason":"failed to parse"}],"type":"mapper_parsing_exception","reason":"failed to parse","caused_by":{"type":"illegal_argument_exception","reason":"unknown join name [snippet] for field [join_field]"}},"status":400}