Adding an external project to autoconf

[Dan Smithers]

Hi,
I am trying to add an external project to my autoconf setup.
Specifically it is zlib, and that already has its own autoconf setup.

I want to be able to pass the compiler to use and extra directives that
are needed to the existing configuration.

I have added it as an extra directory to the top level configure.ac and
Makefile.am files but it doesn't seem to generate any makefile and
generates the make error "no rule to make target 'all'"

I thought that this ought to drop straight in.

thanks

dan