> The most absolute solution might be to not ever run any self-/auto-
> configuration script when building the package but instead to always
> supply pre-defined configurations.  The biggest problem I see with this
> is that then pkgsrc might have to include one config for each supported
> platform and release, which would soon become a nightmare

Hm... But you could create a config.site that set a few specific cache
variables though:

        ac_cv_header_libfoobar_h=no

etc.

The buildlink.mk idea won't work for GNOME and other packages that
install a "foo-config" script that can be used to find the right
CFLAGS/LDFLAGS. (Neither will the config.site idea.) But you could deal
with those by hacking the config scripts themselves.

-- Dan