[oe] COMPATIBLE_MACHINE and no buildable providers

[Frans Meulenbroeks]

Bumped upon the folliwing issue.

If a recipe depends on another recipe but that one does have a
COMPATIBLE_MACHINE and you are not in the list, you get an error like:

ERROR: Required build target "xyz' has no buildable providers.

Is this desired?

Or in other words:
should this be fixed by adding the COMPATIBLE_MACHINE clause to the
recipe that has the depends?
Or should COMPATIBLE_MACHINE be allowed to trickle up so when building
a recipe that depends on another recipe that is not for that MACHINE
one only gets a warning.

This is for instance an issue when doing bitbake world.

Frans