[oe] [OE-core] RFC: meta-oe appends and overlayed recipes

[Paul Eggleton]

On Tuesday 12 February 2013 13:10:05 Richard Purdie wrote:
> On Tue, 2013-02-12 at 09:24 +0000, Paul Eggleton wrote:
> > On Monday 11 February 2013 22:35:47 Richard Purdie wrote:
> > > On Mon, 2013-02-11 at 17:09 +0000, Paul Eggleton wrote:
> > > > *
> > > > meta-oe/recipes-qt/packagegroups/packagegroup-qte-toolchain-target.bba
> > > > ppe
> > > > nd This is adding qwt to the qte toolchain. As far as I am concerned
> > > > this
> > > > is a distro policy decision - Qwt is a third-party library that is not
> > > > part of Qt. I believe this should be moved to the layers for whichever
> > > > distros want this.
> > > > 
> > > > * meta-oe/recipes-qt/qt4/qt4-x11-free_4.8.4.bbappend
> > > > * meta-oe/recipes-qt/qt4/qt4-embedded_4.8.4.bbappend
> > > > These two add MySQL and PostgreSQL support to Qt and Qt/Embedded. I
> > > > see
> > > > this as a distro policy decision; these should move to the layers for
> > > > whichever distros want this. FWIW, this is particularly egregious if
> > > > you've already built Qt, then add meta-oe and find Qt is being
> > > > unexpectedly rebuilt.
> > > 
> > > If these were implemented as PACKAGECONFIG options, then distros would
> > > just need to set the appropriate PACKAGECONFIG for the package in the
> > > distro config and we wouldn't even need the appends...
> > 
> > The thing is the Qt configure options are a little more complicated - many
> > of them are three-state switches (enable built-in, enable as a plugin or
> > disabled). Thus we've opted to split the configuration options into
> > variables for each type. We don't get PACKAGECONFIG's DEPENDS handling,
> > but if we used PACKAGECONFIG we'd lose some flexibility.
> 
> Is there a way we can at least have it behave in a similar way to
> PACKAGECONFIG? Can those configuration variables be set from the
> distro?

Well, the default values are set using ?= in qt4.inc, so there's nothing 
stopping them from being set from the distro config.

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre