traceon does not work with a macro whose name is the empty string

4dr14n31t0r Th3 G4m3r <[email protected]> Tue, 26 Oct 2021 03:02:31 +0200

Newsgroups	gmane.comp.gnu.m4.bugs
Message-ID	<CAOKK28AZoNZJaZM5ghh-_qo80A+5kYcX+Mb4Skaw104NXKK93Q@mail.gmail.com>

This m4 script does not show the trace for the macro whose name is the
empty string:

changequote([,])
define([],[Hello world])
traceon([])
indir([])