[OE-core] [PATCH 2/4] recipes: add x11 to required DISTRO_FEATURES

[Koen Kooi]

Op 30 okt. 2014, om 14:28 heeft Richard Purdie <richard.purdie at linuxfoundation.org> het volgende geschreven:

> On Thu, 2014-10-30 at 14:20 +0100, Martin Jansa wrote:
>> On Wed, Aug 06, 2014 at 01:48:31PM +0200, Martin Jansa wrote:
>>> On Mon, Jul 28, 2014 at 02:18:30PM +0100, Richard Purdie wrote:
>>>> On Thu, 2014-07-24 at 17:22 +0200, Martin Jansa wrote:
>>>>> On Thu, Jul 24, 2014 at 02:52:45PM +0100, Burton, Ross wrote:
>>>>>> On 24 July 2014 14:42, Martin Jansa <martin.jansa at gmail.com> wrote:
>>>>>>> +REQUIRED_DISTRO_FEATURES = "x11"
>>>>>> 
>>>>>> Now I'm wondering why this is the solution.
>>>>>> 
>>>>>> If you attempt to build e.g. gnome-desktop explicitly without the x11
>>>>>> distro feature you understandably get an error message, because
>>>>>> gnome-desktop depends on libx11 which sanity checks the distro
>>>>>> features.  This seems correct.
>>>>>> 
>>>>>> Presumably you're problem is that you're running world builds and
>>>>>> they're producing errors on gnome-desktop because they can't satisfy a
>>>>>> dependency on libx11.  It seems that bubbling up the
>>>>>> REQUIRED_DISTRO_FEATURES tests isn't the right thing to do here - why
>>>>>> can't SkipPackage be handled specially, so if you do bitbake -k world
>>>>>> and libx11 emits SkipPackage, anything that has unsatisfiable
>>>>>> dependencies because of this is also skipped?
>>>>> 
>>>>> We discussed this many months ago and IIRC the conclusion was that user
>>>>> should explicitly say that he wants to skip the recipes which depend on
>>>>> something skipped (so that he is aware of what he is missing).
>>>>> 
>>>>> At that time there wasn't REQUIRED_DISTRO_FEATURES support, so I've
>>>>> created huge list of PNBLACKLISTs to blacklist everything not available
>>>>> in our setup - so I can do world builds without ERRORs at the beginning.
>>>>> 
>>>>> REQUIRED_DISTRO_FEATURES seems to me like reasonable compromise, that's
>>>>> why I've sent this patchset to replace small part of my huge blacklist.
>>>>> 
>>>>> This is the list:
>>>>> https://github.com/openwebos/meta-webos/blob/master/conf/distro/include/webos-recipe-blacklist-world.inc
>>>>> 
>>>>> If someone has time to improve SkipPackage and we really want to skip
>>>>> all depending packages, I would be glad to test such patch (because it
>>>>> allows to easily drop all those blacklists for "depends-on-broken"
>>>>> components)
>>>> 
>>>> The question here is whether we want a system which calculates what it
>>>> thinks is right or that we declare it.
>>>> 
>>>> The risk is that if SkipPackage (now known as SkipRecipe) were to
>>>> automatically "spread", you could in theory break the toolchain, have
>>>> nothing buildable and "bitbake world" would return success.
>>>> 
>>>> Effectively the -k option to bitbake already does the SkipPackage
>>>> "spread" idea since bitbake just removes dependencies until it works. If
>>>> does that in a fairly verbose way but it does so deliberately so you can
>>>> see what is going on.
>>>> 
>>>> The alternative is to declare what a given recipe supports and then we
>>>> can know whether it should be skipped or not under a given circumstance.
>>>> 
>>>> Personally, I'm leaning towards a more declarative approach where we
>>>> specify what should and shouldn't be expected to work. I'm open to
>>>> discussion on it though...
>>> 
>>> I agree with more declarative approach.
>>> 
>>> I don't mind maintaining PNBLACKLIST e.g. for components depending on
>>> something we decided to blacklist ourselves in distro config.
>>> 
>>> But for components like this, where we really know that they won't work
>>> without X11 in DISTRO_FEATURES, I think bitbake should skip them
>>> automatically (thanks to REQUIRED_DISTRO_FEATURES). It already
>>> automatically skips all recipes in xorg-lib directory, why it shouldn't
>>> skip other recipes living somewhere else?
>> 
>> Can we make some decision now?
> 
> Well, I think there was an implied outcome of this:
> 
> a) We don't want to automatically do things, we want something
> declarative
> 
> b) We therefore need to go and add REQUIRED_DISTRO_FEATURES = "x11" to
> some further places.
> 
> As such, I'll take patches.
> 
> Was that what other people understood?

That's how I read it and FWIW, I agree.

regards,

Koen