[yocto] sstate black hole?

[Gary Thomas]

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?

-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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