sig   val start :     just_before_listening:(unit ->                            (unit,                             [> `Database of Trakeva.Error.t                              | `Database_unavailable of string                              | `Dyn_plugin of                                  [> `Dynlink_error of Dynlink.error                                   | `Findlib of exn ]                              | `Failure of string                              | `Fetching_node of                                  Ketrew.Persistent_data.Error.fetching_node                              | `IO of [> `Read_file_exn of string * exn ]                              | `Server_status_error of string                              | `Start_server_error of string                              | `System of                                  [> `File_info of string                                   | `List_directory of string                                   | `Remove of string ] *                                  [> `Exn of exn ]                              | `Target of [> `Deserilization of string ] ]                             as 'propagated_error)                            Unix_io.t) ->     configuration:Ketrew.Configuration.server ->     (unit, 'propagated_error) Unix_io.t   val status :     configuration:Ketrew.Configuration.server ->     ([ `Not_responding of string      | `Running      | `Wrong_response of Cohttp.Response.t ],      [> `Failure of string | `Server_status_error of string ])     Unix_io.Deferred_result.t   val stop :     configuration:Ketrew.Configuration.server ->     ([ `Done | `Timeout ],      [> `IO of           [> `Exn of exn | `File_exists of string | `Wrong_path of string ]       | `Stop_server_error of string       | `System of [> `File_info of string ] * [> `Exn of exn ] ])     Unix_io.Deferred_result.t end