Re: [gentoo-dev] Versioning of eclasses and possibly functions inside ebuilds

[Brian Harring <ferringb@gmail.com>]

On Thu, Dec 29, 2011 at 02:37:07AM +0000, Francesco Riosa wrote:
> 2011/12/28 Zac Medico <zmedico@gentoo.org>:
> > On 12/28/2011 05:12 AM, Francesco Riosa wrote:
> >> Seem to me that append a time slice to the function, in the name or as
> >> a parent function that call the underling function can solve most of
> >> the versioning/deprecation problems
> >
> > I've overheard Arfrever discussing a similar approach in funtoo's irc
> > channel, where the ebuild would set a variable prior to inherit if it
> > wants to use a specific eclass API. For the python eclass, he's planning
> > to have ebuilds set the PYTHON_ECLASS_API variable to use the new API.
> > When the variable is unset, the eclass will default to the older API.
> 
> There is a fundamental difference, with "timeslices" it's not the
> ebuild that select the implementation but the point in time it's used,
> or the user forcing a fake time. From what I've read Artfever approach
> require changes in every ebuild and keeping old functions forever. On
> the other hand it may be risky to change the preferred interface from
> the eclass and not the ebuild.

Respectfully, the proposals thus far (including python eclass bit) are 
going in the opposite direction of maintainability, simplicity, 
robustness.

People have problems as is dealing w/ eclasses changing and their 
dependencies in external repositories not being updated; this 
complicates that issue and introduces the same potential into 
gentoo-x86 itself.  That's not beneficial.

Thing to keep in mind beyond the potential for confusion the proposals 
entail were they implemented, is the implementation itself.  
Timeslices?  python eclass api versions (when people have problems 
figuring out the existing, *singular* version)?  These things aren't 
going to be simple which means more than likely, they're going to 
break, and more than likely it's going to be a PITA to maintain it.

Per the norm, I could be wrong, but reading these proposals, they 
really feel like they need to revisit the notion of 
maintainability/robustness as an actual full fledged implementation, 
beyond the (admittedly semi nifty) notion of versioned apis.

My 2 cents, hopefully not at my usual offensive level-
~harring