Re: HEADS-UP: Library version number bumps

On Wed, Sep 29, 2004 at 08:31:00AM -0400, Ken Smith wrote:
> On Wed, Sep 29, 2004 at 07:27:10PM +1000, Tim Robbins wrote:
> > On Tue, Sep 28, 2004 at 11:05:46PM -0400, Ken Smith wrote:
> > > 
> > > >From the "Better late than never" Department...
> > > 
> > > It looks like we should probably bump the version of a couple of
> > > the system libraries.  With LOTS of help from Kris it looks like
> > > this is the list we think needs a version bump, with the version
> > > from 4.X being placed in compat4x:
> > > 
> > >        libgnuregex.so.2
> > >        libhistory.so.4
> > >        libm.so.2
> > >        libncurses.so.5
> > >        libopie.so.2
> > >        libpcap.so.2
> > >        libreadline.so.4
> > >        libwrap.so.3
> > > 
> > > The bumps will be coming soon...
> > 
> > Why do they need to be bumped? Why use the version from 4.x? It sounds like
> > this will break a lot of 5.x binaries.
> > 
> 
> They need to be bumped because the internal workings of the libraries
> have changed in such a way that a 4.X executable will either be
> un-dynamically-linkable, will fail ungracefully (seg-fault, etc),
> or (worse) run but it makes assumptions that are no longer valid
> thus producing incorrect results.  By putting the older versions of
> the libraries in the compat directory the dynamic linker will find
> and link to those instead when starting the executable and since we
> will have taken them from a 4.X system the executable should run just
> fine.
> 
> Normally development cycles are "much more sane" (Scott's usual phrasing
> for it :-) so at least in theory they're much shorter, and we don't
> usually have as many "end-user-type-people" using a development branch
> as we have now with the 5.X series.  So the fact we do this sort of thing
> hasn't been a huge issue before - the developers should know how to cope
> with it.  You're right - there can be 5.X based binaries that will have
> problems.  At this point we need to decide which old executables break
> and we're opting to break the 5.X executables - at least those users
> had a little bit of a warning they were using a not-for-production-use
> system.  We're not particularly happy about needing to do this.
> 
Can you or Kris post some additional details of what in these
libraries have changed so they can't be used for 4.x binaries?


Cheers,
-- 
Ruslan Ermilov
ru_at_FreeBSD.org
FreeBSD committer