pub fn init_logging()Expand description
Install Day’s default logger and level, unless the app already installed its own.
Called from launch_with, so logging works with no ceremony at all: an app writes
log::info!(…) (or day::info!, the same macro re-exported through the prelude) and the line
comes out on every platform. set_logger answers Err when a logger is already registered;
that is all the customization there is, and why the error is ignored: an app that
called env_logger::init() (or installed tracing, or its own log::Log) before
day::launch keeps it, and Day does not fight for the slot.
The default level is Debug in a debug build and Info in a release one; DAY_LOG overrides
it with a level name (off/error/warn/info/debug/trace). Reading an environment
variable is a native-only affordance; on the web there is no process environment, so the
launch path sets the level explicitly from the page’s query string instead.