[yocto] Navigating the layer labyrinth

[Alexander Kanavin]

On 10/12/2017 12:34 PM, Bernd wrote:
> * Finding the *file path* of an existing recipe (or append file or
> class) *by its name* and also all existing .bbappends for it, i
> imagine something simple like bitbake --show-paths foo-bar would
> output me the small list of absolute paths of recipe files by the name
> foo-bar and all matching .bbappend files in the order in which they
> would be applied, it would show me only this small list of paths and
> not dump 100kb of unrelated information along with it. This would be
> incredibly helpful when I need to inspect an existing recipe in order
> to understand how I can bbappend it or even just to see and understand
> what it actually does.
> 
> * A simple way to track the assignment of a certain variable, to
> inspect its contents and if it refers to other variables then
> recursively show their contents too (and also the path of the bb file
> where this happens), and also show which other recipes will directly
> and indirectrly depend on this variable further down the line, I
> imagine this should output two tree-like structures where one can see
> at one glance how and where all the contents of that variable come
> from and where they are going to be used. Again this should be a
> simple command that formats and outputs that (and only that)
> information in a well formatted and compact tree-like representation.

I think bitbake -e could be of some help with these two things. It's not 
particularly compact, but it tells you the full story.

Alex