aclocal.m4 not regenerated when Makefile.am changes

[Colin Watson]

In a fresh unpacked copy of
http://download.savannah.nongnu.org/releases/man-db/man-db-2.5.1.tar.gz:

  $ touch Makefile.am
  $ ./configure
  $ make
  configure.ac:7: version mismatch.  This is Automake 1.10.1,
  configure.ac:7: but the definition used by this AM_INIT_AUTOMAKE
  configure.ac:7: comes from Automake 1.10.  You should recreate
  configure.ac:7: aclocal.m4 with aclocal and run automake again.
  WARNING: `automake-1.10' is probably too old.  You should only need it if
           you modified `Makefile.am', `acinclude.m4' or `configure.ac'.
           You might want to install the `Automake' and `Perl' packages.
           Grab them from any GNU archive site.

Of course, I have upgraded automake on my system to 1.10.1 since
producing that tarball. But why didn't the rebuild rules just run
aclocal for me? This seems as simple as adding Makefile.am to the
dependencies of $(ACLOCAL_M4).

If nothing else, Makefile.am may contain ACLOCAL_AMFLAGS (and in fact
does in this case), so IMO correct rebuild rules should re-run aclocal
in case those flags changed; although in order to get that completely
right it also ought to fish ACLOCAL_AMFLAGS out of Makefile.am à la
autoreconf ...

Thanks,

-- 
Colin Watson                                       address@hidden