[csw-maintainers] Alternatives without automatic selection

[Peter FELECAN]

Dagobert Michelsen <dam at opencsw.org> writes:

> Hi Peter,
>
> Am 26.11.2010 um 09:36 schrieb Peter FELECAN:
>> Dagobert Michelsen <dam at opencsw.org> writes:
>>> a question arose whetere it is allowed to have two alternatives
>>> with the same priority. The idea is this: If the priorities are
>>> the same the package which gets installed first is kept,
>>> irregardless if other alternatives are installed later.
>>> One usecase would be e.g. an MTA (like sendmail) which you
>>> deliberately install and configure. Than, later, some other
>>> program needs some other mailer which can act as MTA or MUA
>>> which should not override what you have already configured.
>>> You can of course always select alternatives manually.
>>> 
>>> This has the consequence that programs must be installed
>>> in the same order they were removed as automatic same-prios
>>> are not persistently saved on alternative-selection.
>>> This may be necessary, though.
>>> 
>>> Ideas?
>> 
>> I'm not sure on what you're asking ideas...
>
> Would you consider same priorities a bug or a feature?

Definitely a feature! You example shows it clearly.

>> however, for the order of
>> installation you have the installation date of the packages which gives
>> you the order until an unsynchronized update is made; otherwise, the
>> alternatives system can be enhanced to make persistent the alternative
>> selection and priorities,
>
> ATM it is persistent *only* if the selection was done manually.
> If you have two packages pkg1 and pkg2 which are installed in
> order and provide "soft" with the same priority then
> pkg1.soft is selected and kept after installation of pkg2.
> If you update, pkg1 is removed and pkg2.soft is selected.
> On reinstallation of the newer pkg1 there is no switch-back
> until pkg2 is also removed. So even automatic selection should
> be noted and rolled back.

If we implement same priority alternatives and the order of installation
is rendered persistent I think that the described use case is satisfied.

>> if I'm understanding correctly, we now have a
>> specific alternative system, isn't it? or is still based on the Linux
>> one?
>
> Yes, specific. CSW-custom-implemented.

At least we have the advantage to enhance it (although I was opposed to
such a specific implementation now I see the advantage...)

What are the solutions for this issue in the Linux alternatives
implementation?
-- 
Peter