[OE-core] OE-core] How do I find out why are packages being rebuilt?

[Burton, Ross]

On 18 February 2013 11:04, Mike Looijmans <mike.looijmans at topic.nl> wrote:
> I'm still having trouble with packages being needlessly rebuilt over and
> over. The worst of all it qt4-embedded, it takes about an hour to build.
> This is wasting a LOT of time.
>
> The classic OE never rebuilt a package until its version changed.

oe-core uses checksums of dependencies to determine what to rebuild -
so if a class you inherit changes it's populate_packages_prepend()
then the package task will re-execute, or if a dependeny package
rebuilds then your package will rebuild too.  If you're tracking
oe-core master then this often means large rebuilds as there may have
been changes to the base.bbclass or package.bbclass which obviously
impacts everything, and the usual churn in the packages.

bitbake-diffsigs will let you follow the signature differences that
cause a rebuild up the tree to identify what has changed.

Ross