[OE-core] [PATCH] layer.conf: Bumping LAYERVERSION_core

[Flanagan, Elizabeth]

On Tue, Jul 2, 2013 at 2:50 PM, Paul Eggleton
<paul.eggleton at linux.intel.com> wrote:
> Hi Beth,
>
> On Tuesday 02 July 2013 12:20:00 Flanagan, Elizabeth wrote:
>> This goes back to my RFC:
>>
>> http://comments.gmane.org/gmane.comp.handhelds.openembedded.core/39016
>
> Sorry, I meant to reply to that email and didn't get around to it, my
> apologies.
>
>> As we are removing meta-toolchain* and replacing it with bitbake
>> <imagename> -c populate_sdk this causes issues with those of us who
>> need to do automated builds both on the current development branch and
>> on prior development branches.
>>
>> Example: For prior releases, I need to build meta-toolchain*. Without
>> having a simple way to figure out where this is no longer the case, I
>> (and other folks who run automated builds) end up having to jump
>> through a lot of hoops trying to figure out where this layer changed.
>> Utilizing LAYERVERSION_* to do it makes sense as there is a
>> significant change that would cause issues for build engineers. Prior
>> to this I was utilizing LCONF, which was the wrong solution, but just
>> happened to work in the example I'm thinking of.
>
> I can definitely see this being useful as something you can do a conditional on
> within the autobuilder code; however the original intention was that
> LAYERVERSION would only get bumped on changes that would break other layers
> (being that it was designed to match up with versioned layer dependencies) and
> I'm not sure this is one of those changes.
>
> This situation has come up a lot over the life of this project, and I wonder
> if it's time to look at having something a bit more organised - perhaps part
> of the static configuration of the autobuilder could be within the metadata,
> i.e. just the values needed to specify the right version-specific behaviour?
> For the purposes of the Yocto Project autobuilder we can add the needed
> definitions in the meta-yocto layer rather than needing to modify OE-Core.
> Could that work?
>

I really think that this is something that needs to be at the
individual layer level. One of the other reasons why is that, while
admittedly, the yocto-autobuilder is my main concern, I can see people
utilizing a lot of different autobuilders or even different
yocto-autobuilder configurations. We obviously can't track those, nor
should we.

When things change in oe-core (or any layer) enough that an image
definition disappears or changes the way we compose bblayers.conf or
auto.conf, there needs to be something that I can utilize as a
conditional so I can maintain backwards compatibility.

I've been lucky so far in that the times these have come up I can
usually peg off of LCONF_VERSION or a branch name as long as I never
need to build a prior version of the branch. But that is a really
lousy solution that has caused me no small amount of headache and I
can see the instance coming where this is not a viable solution. I'm
more than happy to hear an alternative solution though that helps not
just the yocto-autobuilder but also anyone else utilizing a different
CI system.

> Cheers,
> Paul
>
> --
>
> Paul Eggleton
> Intel Open Source Technology Centre

-b

-- 
Elizabeth Flanagan
Yocto Project
Build and Release