aclocal recursion error

[Skip Montanaro]

I'm struggling trying to get away from some old, locally installed
versions of the autotools on my Mac, deferring instead to the versions
provided by MacPorts.  I recently deleted my versions of libtool and
auto*.  I have the latest versions of those tools installed via
MacPorts (automake 1.10, glibtool 1.9f, autoconf 2.61).

This simple bootstrap script now fails:

    #!/bin/sh
    set -ex
    LIBTOOLIZE=glibtoolize ; export LIBTOOLIZE
    glibtoolize --automake
    aclocal
    autoheader
    automake --foreign --add-missing
    autoconf

It used to be "libtoolize" instead of "glibtoolize" and didn't set the
LIBTOOLIZE environment variable.  (What is the difference between the
two?)

When I execute the above script I get this output:

/opt/local/share/aclocal/smpeg.m4:13: \
        warning: underquoted definition of AM_PATH_SMPEG
/opt/local/share/aclocal/smpeg.m4:13:   \
        run info '(automake)Extending aclocal'
/opt/local/share/aclocal/smpeg.m4:13:   \
        or see http://sources.redhat.com/automake/automake.html\
        #Extending-aclocal
/opt/local/bin/gm4:configure.ac:23: recursion limit of 1024 exceeded, \
        use -L<N> to change it
autom4te: /opt/local/bin/gm4 failed with exit status: 1
aclocal: autom4te failed with exit status: 1

which I'm at a loss to decipher.  I don't use smpeg.  It's just
installed as a side effect of installing other packages under
MacPorts.  I'd be happy to uninstall it, but stuff I do want to use
depends on it.  This simpler variant:

    #!/bin/sh
    set -ex
    libtoolize --automake
    aclocal
    autoheader
    automake --foreign --add-missing
    autoconf

runs just fine on Solaris 10 (automake 1.9.5, libtool 1.5.14, autoconf
2.59).

Can anyone shed some clues on the problem?  Is the AM_PATH_SMPEG
definition indeed the culprit?  It's definition is a big honking mess,
otherwise I'd just post it here (gmane would no doubt complain about
line length).  Instead, I tossed it on the web:

    http://www.webfast.com/~skip/smpeg.m4

Any help appreciated.

Thanks,

Skip Montanaro