[yocto] sstate black hole?

[Martin Jansa]

On Mon, Jun 15, 2015 at 11:41:47AM -0600, Gary Thomas wrote:
> On 2015-06-15 08:21, Martin Jansa wrote:
> > On Mon, Jun 15, 2015 at 07:35:20AM -0600, Gary Thomas wrote:
> >> I'm working with i.MX6 targets (meta-fsl-arm*).  For these
> >> targets, some packages are "special" in that they use i.MX6
> >> specific graphics support.  This ends up with an additional
> >> layer of stratification, so my tmp/work tree has:
> >>     all-amltd-linux
> >>     cortexa9hf-vfp-neon-amltd-linux-gnueabi
> >>     cortexa9hf-vfp-neon-mx6qdl-amltd-linux-gnueabi
> >>     teton_p0382-amltd-linux-gnueabi
> >>     x86_64-amltd-linux-gnueabi
> >>     x86_64-linux
> >>
> >> The packages that are built in tmp/work/cortex* are architecture
> >> specific, not target specific, hence my question:
> >>
> >>     If I build for two i.MX6 targets, identical in every way
> >>     except for the ${MACHINE} name, if I use sstate to share
> >>     the builds from target A when building for target B, why
> >>     are the packages built in cortexa9hf-vfp-neon-mx6qdl-amltd-linux-gnueabi
> >>     not shared by sstate?  I can see that they are present in
> >>     the sstate cache, but they are always rebuilt for target B.
> >>     I consider this incorrect behaviour as these are the same
> >>     architecture and so they should be sharable via sstate.
> >>
> >> Am I missing something here?  How can I determine why the
> >> package from target A (sstate cache) is not usable by target B?
> >
> > Use openembedded-core/scripts/sstate-diff-machines.sh to check if the
> > signatures of the recipes you expect to be re-used are the same.
> >
> 
> How can I use this if the two targets have their own tmp/ tree?

call it twice (once in each tmp tree) and compare resulting list.M files

-- 
Martin 'JaMa' Jansa     jabber: Martin.Jansa at gmail.com