Subject: Re: make update hell
To: Pavel Cahyna <pavel.cahyna@st.ms.mff.cuni.cz>
From: Alistair Crooks <agc@pkgsrc.org>
List: tech-pkg
Date: 10/10/2004 22:46:14
On Sun, Oct 10, 2004 at 04:54:10PM +0200, Pavel Cahyna wrote:
> Hello, thank you for your interest in this discussion.
> 
> > On Fri, Oct 08, 2004 at 01:37:30PM +0200, Pavel Cahyna wrote:
> > > > How do you propose to provide many instances of a library with the
> > > > same major number in the same directory?
> > > 
> > > I don't propose anything like this. Why should there be many instances of
> > > a library with same major number? If the major number is the same, they
> > > are compatible, so one instance should be enough.
> > 
> > So your stance has moved to that of "it doesn't matter what minor version
> > of the shared library is used, because it's compatible through the major
> > version branded into the SONAME in the binary"?
> 
> Yes, exactly. (Of course, one need the minor number to be not less than
> the one with which the program was built. But it is enough to have one
> which satisfies this constraint for all the programs installed, and
> because minor numbers are strictly ordered, one such (that one with the
> highest minor version) should always exist.) Also I don't see how my
> stance has moved, but probably I wasn't clear from the beginning.
> 
> Is this view incorrect?

Well, I don't always trust third-party code to bump major numbers at
the correct time, and for the right reasons, but maybe that's just
rampant paranoia on my part.  In addition, there may be bug fixes in
later versions of a shared library with the same minor number.  Or new
functionality, but not covered by an ABI change.  Or a security fix. 
In general, relying on the major number to be the sole arbiter of
whether or not a library is compatible, wanted and necessary will work
for a lot of occasions, but I would doubt that it would work all the
time for everyone.
 
> > > libraries it seems to be an overkill. I also think that concerns raised by
> > > Greg A. Woods in
> > > http://mail-index.netbsd.org/tech-pkg/2003/08/21/0049.html may be valid.
> > 
> > I am absolutely distraught that Greg's views are different from my own.
> 
> Sorry, I'm not sure that I understand, not being an English native
> speaker.

Oh, it's just that I'd be more worried if Greg and I were to agree.

Regards,
Alistair