class Async::Container::Threaded::Child::Instance

def exec(*arguments, ready: true, **options)

This creates the illusion that this method does not return (normally).
Execute a child process using {::Process.spawn}. In order to simulate {::Process.exec}, an {Exit} instance is raised to propagage exit status. 
def exec(*arguments, ready: true, **options)
	if ready
		self.ready!(status: "(spawn)")
	else
		self.before_spawn(arguments, options)
	end
	
	begin
		pid = ::Process.spawn(*arguments, **options)
	ensure
		_, status = ::Process.wait2(pid)
		
		raise Exit, status
	end
end