[OE-core] Figuring out why sstate-cache is no longer used for a package

[Burton, Ross]

On 10 December 2013 06:44, Mike Looijmans <mike.looijmans at topic.nl> wrote:
> The current situation is that a client will grab everything from the
> buildserver's HTTP sstate-cache, potentially finishing a build from scratch
> in about five minutes. However, for some reason, the fpga-image does not
> fall into this category, and eache machine insists on re-building it from
> scratch. I've been trying to debug this, but the sstate-cache is on another
> machine. I tried copying part of the build server's sstate-cache onto my
> machine, but that only results in "bitbake-diffsigs -t fpga-image .."
> yielding "ERROR: No sigdata files found matching fpga-image .." so that
> apparently is a dead end.

The trick is to use bitbake -S to write stamp data for a particular
image and copy that around. The script sstate-diff-machines can help
here.

Note that there's been some sstate fallout from the recent
optimisations: it was discovered yesterday that sstate hashes using
the "contains()" optimisation wasn't reliable so could produce
different hashes on different machines.  Try oe-core master from today
and see if that's any better: it certainly is for me.

Ross