Am Dienstag, den 24.02.2009, 22:58 +0000 schrieb Ciaran McCreesh:
> On Tue, 24 Feb 2009 23:48:27 +0100
> Luca Barbato <lu_zero@g.o> wrote:
> > Ciaran McCreesh wrote:
> > > Not true. You don't know whether the cache is valid until you know
> > > what the EAPI is.
> > 
> > If you are on the user scenario the cache is valid.
> 
> Uh. Wrong.
> 
> > > Can't use the cache until you know what the EAPI is.
> > 
> > The current cache holds all the current portage needs to know what to 
> > ignore, providing the cache in such format will make portage ignore
> > any future change.
> 
> Uh. Wrong.
> 
> The information used to validate a cache entry is only usable if you
> know the behaviour of 'inherit' that was used to create the entry.
> 
Well, you could theoretical consider everything in the cache valid
within the current scope, find the eapi within the cache or the ebuild
and then reconsider things.
But the problem with this approach (besides performance, etc.) is that
it is not possible to make a pm robust enough to not fail completely
when parsing the cache entry.

The point is: Since the cache format is part of the eapi (since we store
eapi-dependant information in there), the eapi must be known before
parsing the cache data.

Would it be possible to change the cache-format with with G55?
Meaning: Have the current cache-format for the current *.ebuild and
another for *.ebuild-N (where I mean by cache-format the contents of the
cache-files)?