Default variants

[N_Ox]

Le 16 août 07 à 13:47, Rainer Müller a écrit :

> N_Ox wrote:
>>
>> Le 14 août 07 à 19:58, N_Ox a écrit :
>>
>>>
>>> Le 12 août 07 à 05:28, N_Ox a écrit :
>>>
>>>> From what I've understood, the problem with default variants is  
>>>> that
>>>> if we do something like `port foo -bar` and that foo has
>>>> `default_variants +bar`, if an upgrade of foo is released, then  
>>>> `port
>>>> upgrade foo` will enable bar variant because variant disabling are
>>>> not saved and `default_variants +bar` will be evaluated.
>>>>
>>>> Is this really a problem?
>>>> Can't we use the magic of the TCL interpreter and ignore the  
>>>> call to
>>>> default_variants procedure in upgrade variant?
>>>>
>>>> These were my $0.02 for tonight...
>>>> ...I'll now take my pills and go to bed :p
>>>>
>>>
>>> Another problem with default_variants are variant conflicts.
>>> Something among those lines:
>>>
>>> variant apache2 {...}
>>> variant apache conflicts apache2 {...}
>>> default_variants +apache2
>>>
>>> and this port command:
>>> port install +apache
>>>
>>> would produce an error because that would select apache and apache2.
>>>
>>> So here is my idea: let's create a new block named variant_group, or
>>> variant_choice, or even both.
>>>
>>> variant_(group|choice) webserver {
>>>     variant apache2 {...}
>>>     variant apache {...}
>>> }
>>>
>>> variant_group would tell us that we _can_ enable support for _one_
>>> webserver, namely apache or apache2.
>>> variant_choice would tell us that we _must_ enable support for _one_
>>> webserver, namely apache or apache2.
>>>
>>> That's all for today.
>>> Regards,
>>>
>>
>> Almost all...
>> I've forgotten something:
>>
>> default_variants +apache2 and port install +apache would not fail and
>> would automagically select apache instead of +apache2.
>
> No one commented on this yet, so I will do start the discussion. I  
> think
> this is a very reasonable idea to group variants to make it easier to
> implement choices. I also remember that we have some port having a
> choice between gnutls and openssl, so this is really a common use  
> case.
> But there is still the need to record disabled default variants in  
> order
> for this to work.
>
> Rainer

As I've said in the very first mail of this discussion, I don't think  
recording disabled default variants is really a problem.
The only case it is one is during upgrade, and what I've said should  
fix that.

--
Anthony Ramine, the infamous MacPorts Trac slave.
nox at macports.org