val traceln :
?__POS__:(string * int * int * int) ->
('a, Format.formatter, unit, unit) format4 ->
'aWrites trace logging using the current fiber's configured traceln function.
val with_trace_prefix : (Format.formatter -> unit) -> (unit -> 'a) -> 'awith_trace_prefix fmt fn runs fn () with a traceln that outputs fmt before each message.
val traceln_mutex : Mutex.tThe mutex used to prevent two domains writing to stderr at once.
This might be useful if you want to write to it directly yourself, e.g. for a log reporter.
val default_traceln :
?__POS__:(string * int * int * int) ->
('a, Format.formatter, unit, unit) format4 ->
'adefault_traceln is a suitable default implementation for Eio.Std.traceln.
It writes output to stderr, prefixing each line with a "+". If __POS__ is given, it also displays the file and line number from that. It uses traceln_mutex so that only one domain's output is written at a time.
type traceln = {traceln : 'a. ?__POS__:(string * int * int * int) ->
('a, Format.formatter, unit, unit) format4 ->
'a;}val v : tBackends should use this for Eio.Stdenv.debug.