[OE-core] How to find out why shared sstate is not being used for a recipe

[Richard Purdie]

On Wed, 2014-05-28 at 13:46 -0700, Christopher Larson wrote:
> 
> On Wed, May 28, 2014 at 1:42 PM, Khem Raj <raj.khem at gmail.com> wrote:
>         On Mon, May 26, 2014 at 11:58 PM, Mike Looijmans
>         <mike.looijmans at topic.nl> wrote:
>         > I have a deja-vu feeling about this question.
>         >
>         > I have this recipe:
>         >
>         >
>         https://github.com/topic-embedded-products/meta-topic/blob/master/recipes-bsp/fpga/fpga-image-miami.bb
>         >
>         > Which includes this one:
>         >
>         https://github.com/topic-embedded-products/meta-topic/blob/master/recipes-bsp/fpga/fpga-image.inc
>         >
>         > I have a build server that exports its sstate-cache
>         directory through HTTP,
>         > and a local host that attempts to use that sstate-cache.
>         This works fine,
>         > except for the recipe above. Building this recipe takes
>         about 1 hour, so i
>         > really really really want to share that state at any cost.
>         As you can see,
>         > I've done a big shotgun blast of "vardepdsexclude" to get
>         the recipe to be
>         > as common as possible. Still any host wants to build its own
>         version.
>         >
>         > How can I diagnose the REASON that my machine thinks it
>         isn't building the
>         > exact same thing as the build server?
>         
>         
>         see https://wiki.yoctoproject.org/wiki/Enable_sstate_cache
>         towards the end it talks about verifying sstate sigs
> 
> 
> If the sstate is local at least, you can use bitbake -S printdiff
> <target>. There's also bitbake-whatchanged, but the bitbake one is
> superior.

Worst case, you can pull the siginfo files from one build and the
siginfo files from the sstate mirror and then see which ones are
different, then run bitbake-diffsigs X Y to compare the two files.

bitbake -S just tries to automate that process if it can.

Cheers,

Richard