how to add a dependency to destdir?

[Bruno Haible]

Hi,

How can I add a dependency to the 'destdir' target, as generated by automake
and as invoked by the parent directory's Makefile? I need to update some
files before a release.

Example:
========================= Makefile.am =======================
AUTOMAKE_OPTIONS = 1.5 foreign no-dependencies

subconfigure:
        echo "created by autoconf" > subconfigure

distdir: subconfigure
========================= configure.ac ======================
AC_INIT(configure.ac)
AM_INIT_AUTOMAKE(foobar, 0)
AC_OUTPUT([Makefile])
=============================================================

$ aclocal
$ autoconf
$ automake -a -c
Makefile.am:6: `distdir' is a target; expected a variable
$ echo $?
0

Then look into the generated Makefile.in: The distdir dependency is there
but the normal distdir target

distdir: $(DISTFILES)
        $(am__remove_distdir)
        mkdir $(distdir)
        $(mkinstalldirs) $(distdir)/..
        @srcdirstrip=`echo "$(srcdir)" | sed 's|.|.|g'`; \
        ...

is gone.

How can I achieve this? The only way I've found is to comment out the
dependency line in Makefile.am:
========================= Makefile.am =======================
AUTOMAKE_OPTIONS = 1.5 foreign no-dependencies

subconfigure:
        echo "created by autoconf" > subconfigure

#distdir: subconfigure
=============================================================
and to postprocess the Makefile so as to remove the '#' mark.
This is hardly satisfactory.

Bruno