pub fn init(service: Service) -> Result<LogGuard>Expand description
Install the DIG logging stack for service (SPEC §1). Call ONCE at process start; a second call
returns Error::AlreadyInitialized.
Only two conditions still fail: a subscriber already installed, and — impossible in practice,
since [filter] falls back to a known-good directive — an unparseable filter. An unwritable log
directory does NOT fail; it degrades to console-only logging with a warning on stderr.