Re: Extracting configuration info from config.status

[Brian Dessent]

Barry Leslie wrote:

> It would be really useful if there was a configure option that would allow
> you to point to another location and tell configure to get it's settings
> from there.

If you just want to get the content of variables from a foreign build
dir you can run it's config.status with --file=FILE[:TEMPLATE] or
--header=FILE[:TEMPLATE] and it will instantiate FILE from TEMPLATE
performing the normal AC_SUBST style substitutions, even if TEMPLATE is
something you created and is not part of the foreign tree.

But the quoted text seems to imply you want to do even more than that,
to actually have access those variables during the execution of the
configure script.  In that case you'd probably want to try sharing a
config cache between them.  But this assumes that the foreign project
was configured with caching enabled, and if you don't have control over
how the foreign project was configured you can't assume that it was. 
(It also comes with a whole other set of assumptions, like the
assumption that the foreign project's macros use cache-friendly variable
names or that the things you want to check are even cacheable at all.)

Brian