On Oct 20 12:03, Yaakov Selkowitz wrote:
> On Tue, 2015-10-20 at 17:50 +0200, Corinna Vinschen wrote:
> > > Adding epoch parsing would be additional work.  I'm not sure how much value
> > > that would have since (a) we are effectively limited to 2 package versions,
> > > and (b) we can force a given ordering using setup.hint
> > 
> > Yaakov thinks we need epoch.  Yaakov, could you briefly outline why we
> > should need it?  Do we have real-world examples in the distro where we
> > could need it?  I guess Achim's perl packages are particulary nice
> > examples?
> 
> First, let's remember that this isn't just about upset getting prev: and
> curr: right, but also about setup knowing when to upgrade by default.
> Therefore, simply tweaking setup.hint files is insufficient.
> 
> Besides sorting out our current discrepancies, here is a perfect example
> of a use for epoch:
> 
> https://cygwin.com/ml/cygwin-announce/2015-07/msg00015.html
> https://cygwin.com/ml/cygwin-announce/2015-07/msg00050.html
> 
> In short, xdelta was updated from 1.x to 3.x, then it was realized that
> both were needed, and so xdelta was reverted to 1.x and xdelta3 was
> created.  Instead of saying "oh btw you need to revert xdelta to 1.x
> yourself" (which is all we could do currently), the solution would be to
> bump epoch on xdelta-1.x, which would force it to be considered newer
> than the short-lived xdelta-3.x by both upset and setup.
> 
> As for implementation, the idea would be to use a special character in
> the version number of tarballs as so (pseudocode):
> 
>     char epoch[N] = {}, *sep;
>     if ((sep = strchr(version, SEPARATOR))) {
>       strncpy(epoch, version, sep - version);
>       version = sep + 1;
>     } else
>       epoch[0] = "0";
> 
> Then compare epochs first, then version and release to determine which
> is newer.  As for the separator, in RPM it is ':' but as we will need to
> have this character in the tarball name and Windows doesn't allow that
> in filenames, we will need to pick something else.

SEPARATOR=@

?

> On the cygport side, this would be triggered by defining EPOCH in
> the .cygport file, *not* by using this character in VERSION.

And adding an extra test for the epoch doesn't seem overly tricky
in setup.  Upset, well, Jon?


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat