[yocto] Changing metadata during bitbaking

[Paul Eggleton]

Hi Ash,

On Thursday 15 May 2014 21:41:55 Ash Charles wrote:
> Under what conditions can I change the content of layers without
> affecting an ongoing bitbake?
> 
> On occasion, I find myself wanting to do git operations on my layers
> while I've got a build going on.  I've typically assumed this might
> screw up bitbake but was wondering that my assumption isn't really
> accurate.  Specifically, are these rules reasonable?
> - don't mess around with the content of layers while bitbake is parsing
> - once bitbake has parsed and started baking, playing around with
> metadata should not affect the current build
> - source/config files (i.e. any file:// in SRC_URI) may be fetched at
> any time therefore don't mess around with files that might be used in
> a build

That's pretty much what I follow, although I try to avoid modifying recipes at 
all while there's a chance they might be built - recipes *do* get re-parsed 
during execution, not just when parsing to populate the cache at the start 
(since the cache doesn't contain all variables and functions, just the ones 
that BitBake needs to look up quickly).

Whether or not it's safe to do really depends on what kind of build you're 
doing. If you're just in the middle of development, no big deal; if you're 
doing your final build for a release then you probably shouldn't risk it.

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre