Logs.LOGThe type for source specific logging functions.
val app : 'a logapp is msg App.
val err : 'a logerr is msg Error.
val warn : 'a logwarn is msg Warning.
val info : 'a loginfo is msg Info.
val debug : 'a logdebug is msg Debug.
result value Errorsval on_error : 
  ?level:level ->
  ?header:string ->
  ?tags:Tag.set ->
  pp:(Stdlib.Format.formatter -> 'b -> unit) ->
  use:('b -> 'a) ->
  ('a, 'b) result ->
  'aSee Logs.on_error.
val on_error_msg : 
  ?level:level ->
  ?header:string ->
  ?tags:Tag.set ->
  use:(unit -> 'a) ->
  ('a, [ `Msg of string ]) result ->
  'aSee Logs.on_error_msg.