pub fn init_tracing(settings: &LogSettings) -> Result<WorkerGuard>Expand description
Initialize the process-global tracing subscriber: a non-blocking rolling file writer
under settings.dir, plus a stderr writer when a console is actually attached (a
scheduled/cron invocation typically has none). Never touches stdout – see the module
doc comment.
Returns the WorkerGuard, which the caller must hold for the process lifetime –
dropping it early silently truncates buffered log lines that haven’t yet been flushed to
disk on exit. A logging setup failure (e.g. an unwritable log directory) is not fatal to
the CLI’s command or the server’s primary service, so their startup paths treat the
returned Err as best-effort rather than propagating it.