[OE-core] RFC: Layer tooling brainstorming

[Martin Jansa]

On Mon, Apr 18, 2011 at 07:17:01AM +0100, Richard Purdie wrote:
> Layer Tooling for OpenEmbedded
> ==============================
> 
> As we move forward with encouraging the use of metadata layers, a number
> of issues are appearing which imply the need for either infrastructure
> improvements to the layer construction, or better tools to handle the
> layers. The OS TSC discussed layers and layer tooling at the face to
> face TSC meeting in San Francisco. Some example problems that were
> identified that currently need addressing in some form are:
> 
> * There is no dependency information between layers (layer X depends on 
>   layer Y and Z)
> * There is no version information present (layer X needs version A of 
>   layer Y)
> * There is no layer "ABI" version number present in layers
> * Layer specific sanity checks? (other types of sanity checks on Yocto 
>   1.1 roadmap)
> * Ability to fetch layers from other repositories
>   - Multi SCM?
>   - Use bitbake fetcher?
> * Ability to generate repositories representing composited layers (Poky,
>   RP has hacky scripts)
> * Tool to seperate patch into one for different composited parts
> * Ability to include partial components of repositories (e.g. only 
>   beagleboard from meta-ti)
> * Tool to merge (flatten) several layers into one
> * Able to visualise dependencies between layers
> * When bitbake prints banner of branch/commit, need to cover all layer 
>   components present
> * bitbake -e on steroids to highlight differences due to layer changes? 
>   (long term goal)

maybe I've missed something, but
* Parsing error when ie foo_1.0.bbappend is found, but foo_1.0.bb in
  upper layer was upgraded to foo_1.1.bb

This can cause big problems when distribution explicitly enables
something in .bbappend with EXTRA_OECONF, and someone updates all
layers, builds foo_1.1.bb and installs it on targets before noticing
that foo_1.0.bbappend wasn't used. Then he has to bump PR after adding
foo_1.1.bbappend to distro layer (to fix foo on targets), so I would
prefer parsing error in this case (won't help if upper layer keeps both
versions foo_1.0.bb and foo_1.1.bb ;/).

This should be combined with your 2nd point and person who changes
versioned dependency on upper layer should check that all needed
.bbappends still apply.

Regards,

-- 
Martin 'JaMa' Jansa     jabber: Martin.Jansa at gmail.com