[yocto] Variable locality too restricted.

[David Nyström]

Hi, 

I'm trying to create a setup for qemuppc.

Goals:
core-image-minimal + virtual/kernel. 
core-image-minimal + virtual/kernel with modified .config for debug flavoured kernel.

Problems:
PREFERRED_PROVIDER seems to be restricted to local.conf, distro and machine.

Creating another machine for my debug flavored kernel feel wrong. creating a new distro even worse.
And I don't want 'sed' my local.conf files everytime I want to switch flavors.

Possible solution:
The possibility to set PREFERRED_PROVIDER in image.bb would solve my problem.

Whats the right way to get this done ?

Best Regards,
David