[OE-core] [bitbake-devel] [RFC bitbake][RFC PATCH 1/1] cooker: rework LAYERDEPENDS versioning so that it is actually useful

[Mark Hatle]

On 1/29/15 7:49 AM, Paul Eggleton wrote:
> We've had versioned dependency support in LAYERDEPENDS for quite a long
> time, but I can say with pretty good certainty that almost nobody has
> used it because it was too strict - the specified version had to exactly
> match the version in your configuration or you would get an error; there
> was no "greater than or equal" option, which is usually what you will
> want given that LAYERVERSION does get bumped.
> 
> However, users mismatching layer branches and then having their builds
> fail later on with some incomprehensible error is still a pretty common
> problem. To address this, I have reworked LAYERDEPENDS version
> specifications to use the more familiar "dependency (>= version)" syntax
> as used with package dependencies, support non-integer versions, and
> clarified the error message a little. If we then take care to bump the
> version on every breaking change, it is at least possible to have layers
> depend on these changes when they update to match; we can now even
> support a major.minor scheme to allow retrospectively adding a version
> limiter to old branches when a new branch is created and yet still allow
> the old branch minor version to be bumped if needed.
> 
> Fixes [YOCTO #5991].
> 
> Signed-off-by: Paul Eggleton <paul.eggleton at linux.intel.com>

I've run into this exact support situation as well.  I think we need to do
something like this >, =, <, etc.. so that we can add the necessary keys to
layers to more clearly indicate what is and isn't supported (combination wise.)

I'm all for this!

--Mark