> From this perspective, the "newest" a.out libraries aren't
> "compatible" with "old" NetBSD.  e.g. I can't really use libc.12.40
> instead of my libc.so.12.5 on an older version of NetBSD.

You can't?  Then a minor number bump is insufficient; the major number
should have been changed.

What incompatability do you see?  It should be fixed....

> The "features" in libc have changed, but the features of the kernel
> that libc uses have also changed. (e.g. new syscalls, etc)

That's what call versioning (__RENAME() and company) are all about.

					der Mouse

			       mouse@rodents.montreal.qc.ca
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