[oe] Best practise using .bbappend

[Paul Eggleton]

On Friday 10 August 2012 12:06:28 Paul Eggleton wrote:
> > Should I be setting a PREFERRED_VERSION_bar somewhere, say in the conf
> > for my new layer, on any recipe that I add a .bbppends to, or what's best
> > practise for dealing with this?
> 
> Setting a PREFERRED_VERSION_ for each bbappended recipe is a reasonable
> approach assuming this is a layer intended to apply some policy (i.e. a
> distro layer).
> 
> In practice this is unlikely to come up too often - in OE-Core we usually
> delete the old recipe when upgrading to a new version, and thus if you have
> a bbappend for the old version in your layer you will get an error after
> parsing indicating the bbappend had no matching recipe.

I forgot to mention, "bitbake-layers show-appends" will warn if there is a 
bbappend for one version of a particular PN but none for the current preferred 
version; thus it can be used to catch where this situation has occurred, the 
old recipe was not deleted and no PREFERRED_VERSION_ has been set.

In general bitbake-layers is quite a useful utility for querying layer 
configuration and interaction.

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre