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* Re: [gentoo-pms] Rephrasing *DEPEND
  @ 2011-06-12 18:03 99%           ` Zac Medico
  0 siblings, 0 replies; 1+ results
From: Zac Medico @ 2011-06-12 18:03 UTC (permalink / raw
  To: Michał Górny; +Cc: gentoo-pms, Ulrich Mueller, Ciaran McCreesh

On 06/12/2011 06:16 AM, Michał Górny wrote:
> On Sun, 12 Jun 2011 02:13:35 -0700
> Zac Medico <zmedico@gentoo.org> wrote:
> 
>> On 06/12/2011 01:18 AM, Ulrich Mueller wrote:
>>>>>>>> On Sun, 12 Jun 2011, Michał Górny wrote:
>>>
>>>> True. How about pkg_setup()? Shall we assume RDEPEND are there or
>>>> rely on @system only?
>>>
>>> IIUC, with Portage's breaking of dependency cycles there's no
>>> absolute guarantee that packages in RDEPEND will be available in
>>> pkg_*.
>>
>> It would be more accurate to say that it's guaranteed except for cases
>> in which circular dependencies make it impossible to guarantee.
> 
> This or other words, this makes this an unreliable feature. So, right
> now, users can't assume anything specific about dependencies being
> installed in pkg_*?

In practice it's very reliable, although the specific behavior varies
depending on whether or not there are circular dependencies. So, it
would probably make sense to specify it like this:

(A) If there are no circular RDEPEND dependencies, then RDEPEND is
guaranteed to be satisfied.

(B) If there are circular RDEPEND dependencies, then RDEPEND is not
guaranteed to be satisfied.

> Doesn't this make it actually impossible to call
> the installed application in pkg_postinst()?

Only when case (B) applies. It may be possible to improve a situation
like this by making the circular dependency PDEPEND in one direction and
RDEPEND in the other:

  first RDEPENDs on second
  second PDEPENDs on first

This make it possible to guarantee case (A) for the first package, while
there is no such guarantee for the second package.
-- 
Thanks,
Zac



^ permalink raw reply	[relevance 99%]

Results 1-1 of 1 | reverse | options above
-- pct% links below jump to the message on this page, permalinks otherwise --
2011-06-11  7:32     [gentoo-pms] Rephrasing *DEPEND Michał Górny
2011-06-11 11:53     ` Ciaran McCreesh
2011-06-12  7:52       ` Michał Górny
2011-06-12  8:18         ` Ulrich Mueller
2011-06-12  9:13           ` Zac Medico
2011-06-12 13:16             ` Michał Górny
2011-06-12 18:03 99%           ` Zac Medico

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