Re: [gentoo-dev] RFD : .ebuild is only bash

[Zac Medico]

On 03/13/2012 07:38 PM, Brian Harring wrote:
> On Tue, Mar 13, 2012 at 07:05:57PM -0700, Zac Medico wrote:
>> If all package managers adhere strictly
>> to these two requirements, then we won't have any incompatibilities
>> between package managers here.
>
> You're missing a lot of the point here; defining some search algo is
> basically screwed at its core due to the flexibility of bash.  Simple
> example:
>
> if [ "$PV" -eq 9999 ]; then
> EAPI=3
> else
> EAPI=2
> fi
>
> The flexibility of bash means that your attempt to enforce simplistic
> rules like "it must be greppable" are at loggerheads; if the rules
> were "last is the one thats used", then I just invert the if check.
>
> Yep, the above is stupid code.  Frankly, the sort of stupid code
> I'd expect out of a newbie ebuild dev.  The EAPI bit there is
> synthetic, but that sort of construct (putting everything into a
> single file, then using symlinks to expose differing versions) is out
> in the wild and used.
>
> The fact that potential exists is a flat out sign the approach is
> broken.   Worse, it's a way to trip up people- specifically new devs
> who don't know fun rules like "the PM has this lovely search algo for
> getting EAPI that you must abide by".

It won't be a problem because the package manager can reject the ebuild
as soon as the dev tries to execute it the first time, and it will refer
the dev to the section of PMS that specifies the search algorithm.

As for ebuilds in the wild that already do stuff like that, it's not a
problem if we only require the search algorithm to work starting with
EAPI 5.
-- 
Thanks,
Zac