pub fn main(&self) -> JoinHandle<Result<(), CriticalError>> {
		trace!("notifying start lock");
		self.start_lock.notify_one();

		debug!("handing over main task handle");
		self.handle
			.take()
			.expect("Watchexec::main was called twice")
	}
Start watchexec and obtain the handle to its main task.

This must only be called once.

# Panics
Panics if called twice.
crates/lib/src/watchexec.rs