Re: pkg/46308: pkg_add should not display warnings for known compatible platform mismatches

[Havard Eidnes <he%NetBSD.org@localhost>]

The following reply was made to PR pkg/46308; it has been noted by GNATS.

From: Havard Eidnes <he%NetBSD.org@localhost>
To: gnats-bugs%NetBSD.org@localhost, joerg%britannica.bec.de@localhost
Cc: pkg-manager%netbsd.org@localhost, pkgsrc-bugs%netbsd.org@localhost, 
jschauma%netmeister.org@localhost
Subject: Re: pkg/46308: pkg_add should not display warnings for known
 compatible platform mismatches
Date: Sun, 08 Apr 2012 00:06:14 +0200 (CEST)

 >  >  We have incomaptible minor versions?  That seems like a problem t=
 o me.
 >  >
 >  >  How about compatibility across tiny versions?
 >
 >  Well, 5.1 is the state of the netbsd-5 branch at some point between
 >  5.0.0 and 5.1.0 release, right?
 
 No.  There are no 5.0.0 or 5.1.0 releases.  Instead, we call these
 releases along the netbsd-5 branch 5.0 and 5.1 respectively.  Kernels
 built from the netbsd-5 branch between the releases of 5.0 and 5.1 is
 designated 5.0_STABLE.
 
 >  So it might have the new X libraries or might not have
 >  them. Impossible to tell. x.y.z and x.y.z+1 are most likely
 >  compatible, not sure if we ever pulled up a binary incompatible ABI
 >  change. I'd still say it is backwards compatible only, e.g. new
 >  functions may exist in z+1.
 
 I vaguely remember us at one point bumping the major of a library
 between minor releases.  So to use packages built on the older
 version, you'd have to also have the library with the old major
 present, e.g. via a compat package.
 
 I don't think we've ever made a change which broke backward
 compatibility in any more serious way(?)  At least that's clearly not
 the intent.
 
 So... Packages built for a lower-numbered release should at least be
 usable on another release of the same major, and possibly also on
 newer major releases.  So ... packages built on 5.0 should be usable
 on both 5.0, 5.1 and 5.1.2 etc., and packages built on 5.0.2 should
 also be usable on both 5.1 and 5.1.2, and chances are very good that
 they'll be usable also on 5.0 as well, since we're only supposed to
 fix serious security-related issues in tiny releases, something 5.0.2
 is an instance of.
 
 Of course, there will always be a few packages which are so tightly
 coupled to the particular version of the OS it is built for, but those
 are few and far between.
 
 Regards,
 
 - H=E5vard