https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96890
--- Comment #5 from anlauf at gcc dot gnu.org ---
(In reply to Steve Kargl from comment #4)
> Ping Thomas. I recall seeing that he recently was
> asking about --enable-maintainer-mode in a git
> world.
Hacking the Makfile in x86_64-pc-linux-gnu/libgfortran/Makefile
and manually activating the dependency
$(i_iall_c): m4/iall.m4 $(I_M4_DEPS1)
$(M4) -Dfile=$@ -I$(srcdir)/m4 iall.m4 > $@
does the job, too.
Ugh.
