Binary packages not rebuilding against updated libraries

[Perry E. Metzger]

On Thu, 26 Apr 2018 10:03:59 -0500 Ryan Schmidt
<ryandesign at macports.org> wrote:
> On Apr 26, 2018, at 10:00, Perry E. Metzger wrote:
> 
> > On Thu, 26 Apr 2018 23:54:49 +1000 Joshua Root wrote:  
> >>> So rather than just guessing based on things like major version
> >>> of a library whether dependents need to be bumped, I would
> >>> suggest we add an "abiversion" keyword. Changing it in any way
> >>> would imply that ports depending on that port would be
> >>> rebuilt.    
> >> 
> >> So this would have to be set manually for every library port? If
> >> looking at the library version information is "guessing", how
> >> would the correct value be determined?  
> > 
> > Looking at the library version isn't guessing for a human but
> > might be guessing for a machine. If the version is something like
> > 4.7.3 and it's using semantic versioning, it's probably
> > reasonable to pay attention. If it's not using semantic
> > versioning, like if it's something like 20170815 or some such
> > because it's a weird "built off a github rev" thing, it probably
> > needs a way for a human to convey it.  
> 
> You're talking about the package version, i.e. the version number
> the developer puts in the tarball name, readme, git tag name, etc.
> We're talking about the library version, i.e. the version number in
> the dylib name.

Not quite. I'm noting that the package version isn't a reliable
indication of the ABI version, and neither (sadly, see the current
protobuf issues and the issues with LibreSSL) is the library dylib
name. Thus I'm proposing to have an internal ABI revision number that
we can use for deciding whether dependents need a rebuild.

And again, note that this might be a profoundly stupid idea. I'm just
trying to motivate a discussion on how to automate things so that it
isn't necessary to revbump dependents. And again, it might be vastly
more work than is worthwhile. I'd just like to figure out what might
be a practical way to do it so one can then decide it isn't worth it
or that it is...

> >> The library version info is recorded in the binaries. Rev-upgrade
> >> works very well in most cases. I'm having a hard time
> >> understanding how this would help.  
> > 
> > Well, right now we're manually bumping "revision" in dependent
> > ports when we upgrade a port that is depended on, right? This
> > seems to indicate that the current way isn't automatic. Or maybe
> > I'm misunderstanding?  
> 
> You're correct.

Perry
-- 
Perry E. Metzger		pmetzger at macports.org