Re: [gentoo-dev] RFC: Eclasses and EAPI

[Kristian Fiskerstrand]

On 09/06/2016 12:44 PM, Kent Fredric wrote:
> On Mon, 5 Sep 2016 15:03:36 +0200
> Michał Górny <mgorny@g.o> wrote:
>
>> On Fri, 2 Sep 2016 18:13:20 +0200
>> Kristian Fiskerstrand <k_f@g.o> wrote:
>>
>>> I'm wondering whether it wouldn't make sense to require eclasses (or
>>> strongly encourage) to include an explicit list of EAPIs it has been
>>> tested for in order to ease testing when introducing new EAPIs.
>>>
>>> We have seen some issues already with EAPI6 bump related to get_libdir
>>> and people updating EAPI in ebuild without properly testing the
>>> inherited eclasses. having a whitelist in place and die if eclass is not
>>> updated to handle it solves it.
>>>
>>> Thoughts? comments? cookies? threats?
>>
>> +1. Because:
>>
>> 1. it makes it possible to change API safely with EAPI bump, including
>> major refactorings,
>>
>> 2. it makes it possible for the eclass maintainer to confirm that
>> the eclass is correctly ported to new EAPI, rather than some random
>> developer with poor knowledge of eclass assuming it works fine,
>>
>> 3. it makes it possible to ban the eclass in a new EAPI to more
>> effectively phase it out.
>>
>> This only reminds me of the cases when eclasses weren't calling
>> eapply_user in EAPI 6 and caused ebuilds to fail. Because someone
>> assumed that if his ebuild works in EAPI 6, then the eclass is
>> certainly correct.
>>
>
> My only question is how we enforce it.
>
> Given that eclasses are themselves without EAPI, and relying on this
> check existing in PMS would require such a feature defined in a future EAPI
>
> I suspect for the forseeable future we're going to need to double our effort,
> having a whitelist that is only able to be interpreted by PMS clients that implement
> EAPI7, and then the traditional logic for Pre-EAPI7.
>

I believe you're overthinking it, if we make it a guideline to include a
section of the eclass (as many already have) that does e.g (take this
for example purposes) there is no EAPI/PMS change needed
case "${EAPI:-0}" in
	4|5|6)
	;;
     *) die "EAPI=${EAPI} is not supported" ;;



-- 
Kristian Fiskerstrand
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