PAssing command line arguments for AC_CONFIG_SUBDIR

[Niels Möller]

Is there any way to make configure pass extra arguments when running
configure scripts in a sub directory with AC_CONFIG_SUBDIRS? To be a
little more concrete, my problem is as follows:

In lsh I have a toplevel configure script, which uses
AC_CONFIG_SUBDIRS to run configure in the subdirectories src/nettle
and src/spki. Both of these subdirectories are libraries, and can be
distributed and built separately.

The spki library depends on nettle. So when building the spki
directory separately, it should use configure tests for nettle and use
the nettle library that is installed on the system. However, when
building both libraries as parts of lsh, I want to use the included
nettle library, and ignore any library which is already installed on
the system.

One way of doing this is to let spki:s configure script take a command
line argument --with-nettle=<nettle-directory>, and use that to set up
-I and -L-flags etc properly.

But then I need lsh:s configure script to add the option on the
command line when invoking spki's configure script. Can I do that?

Or is there some better way of solving the problem? I can think of
some kludges involving symlinks created by lsh:s configure script, but
that seems pretty ugly.

Regards,
/Niels

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