I would like to see Gtkmm implement a mechanism for ensuring that programs
compiled against Gtkmm 2.2 (and in the future, 2.4), cannot be linked
against Gtk 1.x libraries without a link-time error.  If that isn't
practically possible, then an informative library initialization-time error
would be a decent fallback.  As it currently stands, you can link a Gtk 2
application against Gtk 1 libraries, or a mixture of both versions of the
libraries.  The program then crashes with a segmentation fault at runtime.
 This cause of this segfault is not always immediately apparent, even to
programmers.  As a somewhat public example, a few months ago, a build of
Evolution 1.2 was shipped on Debian Sid that was linked against both Glib 2
and 1.2 libraries.  Several days passed with many complaints before the
source of the crash was found.

Preferably, the reverse should also be true; Gtk 1 applications should fail
to link against Gtk 2 libs.

I really don't have any idea how to implement this kind of protection, but
I think I remember seeing some kind of ABI warning when linking GNU C++
programs against the wrong version of libstdc++.

Thanks,
Jonathan Brandmeyer