On Mon, Aug 02, 2004 at 03:02:05AM +0100, Andrew Suffield wrote:
> On Sun, Aug 01, 2004 at 02:03:06PM -0600, Joel Baker wrote:
> > Not that it's the right solution for this, but it happens to be the ONLY
> > solution when you need to version a virtual dependancy (IE, multiple
> > packages can legitimately provide implementations of a specific API, and
> > the things that use that API don't care which one does, as long as something
> > is there).
>
> That would indicate a much more strongly defined ABI than the one of a
> regular shared library - like the perl ABI. These things are
> maintained upstream in a rigorous manner, in both forwards *and*
> backwards directions, in order to make ABI compatibility work at
> all. Very different beast, and the properties I just outlined are the
> reasons why it works there, and not here.
>
> [Note that such a thing is still distinct from the library ABI, even
> if it happens to be implemented in a library, and should be versioned
> in a completely independent manner].
That would be why I said it wasn't the right solution for the library issue;
mostly I was just noting it existed (and in fact, for kernels, is often going
to look something like:
Provides: kernel-abi-1-0, kernel-abi-1-1, kernel-abi-2-0
Since it is exceedingly common for BSD-land kernels to provide emulation
abilities for older ABIs (in fact, it's more or less required, so that
you can boot under the new kernel long enough to do 'make installworld'
on the rest of the core system, which has to talk to both old and new
core-userland stuff like 'ps', which is their way of upgrading).
Anyway. I think we're in (not so) violent agreement here. Anything which
thinks it needs this should have a clear and obvious reason that it makes
sense (though I still wish we had versioned virtual dependancies, but
that's huge bucket of nastyness that *still* wouldn't necessarily resolve
situations like the above...)
--
Joel Baker <fenton@debian.org> ,''`.
Debian GNU/kNetBSD(i386) porter : :' :
`. `'
http://nienna.lightbearer.com/ `-
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