The automatic distribution of dx-stamp.m4 depends on m4_include
appearing in the m4 traces. Normally aclocal does that but it
seems to not be entirely reliable. The reason we do not simply
use m4_include is because this produces warnings about multiple
inclusion.
Fortunately, this is pretty easy to work around. Just use m4_pushdef
to redefine m4_include to what we need, so the traces show the file
needs to be distributed.
dnl Include the stamp file, which will cause a failure at autoconf time
dnl if it does not exist in the checkout. We circumvent m4_include to
dnl avoid warnings about multiple inclusions.
-m4_builtin([include], m4_defn([_DX_BASEDIR])[/m4/dx-stamp.m4])
+m4_pushdef([m4_include], [m4_builtin([include], $][@)])
+m4_include(m4_defn([_DX_BASEDIR])[/m4/dx-stamp.m4])
+m4_popdef([m4_include])
_DX_STAMP_DUMMY
dnl Autoconf scripts should use the DX_BASEDIR m4 macro instead of the