[yocto] under what circumstances is BBCLASSEXTEND = "native" required in a recipe?

[Chris Larson]

On Sat, Aug 11, 2012 at 10:03 AM, Robert P. J. Day
<rpjday at crashcourse.ca> wrote:
>   however, the "chrpath" command is not listed in bitbake as part of
> ASSUME_PROVIDED, and its recipe includes the line
>
>   BBCLASSEXTEND = "native"
>
> that's what's confusing -- if the QS guide demands that the user
> install "chrpath" manually, what is the subsequent value of its recipe
> dictating that it be natively buildable?

At a guess, it's possible that not all recipes that needed
chrpath-native had an explicit dependency on it, or similar. Your
question is specific to chrpath, not at all general to BBCLASSEXTEND.
Adding native to bbclassextend means that a -native version of the
recipe can be built. The question of why certain things are expected
on the host vs built from that recipe is an entirely different one.
-- 
Christopher Larson