500 error showing some merge requests

https://sentry.gitlab.net/gitlab/gitlabcom/issues/810604/

GRPC::DeadlineExceeded: 4:Deadline Exceeded
  grpc/generic/active_call.rb:31:in `check_status'
    fail GRPC::BadStatus.new_status_exception(
  grpc/generic/active_call.rb:181:in `attach_status_results_and_complete_call'
    recv_status_batch_result.check_status
  grpc/generic/active_call.rb:170:in `receive_and_check_status'
    attach_status_results_and_complete_call(batch_result)
  grpc/generic/active_call.rb:338:in `each_remote_read_then_finish'
    receive_and_check_status
  gitlab/gitaly_client/conflict_files_stitcher.rb:15:in `each'
    @rpc_response.each do |msg|
...
(137 additional frame(s) were not displayed)

GRPC::DeadlineExceeded: 4:Deadline Exceeded

Related Support Tickets (internal)

• https://gitlab.zendesk.com/agent/tickets/125718