[OE-core] sstate breakage with multimachine

[Richard Purdie]

On Tue, 2011-05-17 at 13:37 +0200, Martin Jansa wrote:
> On Tue, May 17, 2011 at 10:42:52AM +0100, Richard Purdie wrote:
> > On Tue, 2011-05-17 at 09:14 +0200, Martin Jansa wrote:
> > > there is also another source of many sstate rebuilds. I've discuessed
> > > this with RP on IRC already and I'll fill bugs as recommended, sharing
> > > here just because you have opened this topic.
> > > 
> > > If you have package with
> > > PACKAGE_ARCH = "all"
> > > then the resulting package is created by run.* scripts with different
> > > pathsi, *FLAGS etc even when it produces same output (ie some theme).
> > > 
> > > So all packages with such PACKAGE_ARCH are rebuilt after machine switch
> > > (if the machine is ie different arch like om-gta02/nokia900).
> > > Sstate is reused when you go back to om-gta02 after building nokia900,
> > > so you have ie populate_sysroot only with as many checksums as you're
> > > building different archs.
> > > 
> > > RP said, that right fix is to introduce something like all.bbclass which
> > > excludes all variables which shouldn't change the output of such package
> > > and then checksums will be the same.
> > 
> > I think rather then exclude them, we should zero them out or unexport
> > them and stop them being present in the task environment. We should file
> > a bug about this problem in the Yocto bugzilla.
> 
> Already did in morning
> http://bugzilla.yoctoproject.org/show_bug.cgi?id=1075

Its not finished but here is a start at this:

http://git.yoctoproject.org/cgit.cgi/poky-contrib/commit/?h=rpurdie/allarch&id=0944f7393054a91ce1508ec1a98bd4c612ee90e4

I fixed up encodings to compile (without trying to us a compiler). The
same kind of fixes are needed for gnome-icon-theme, font-alias and
possibly others. If they are truly "all" arch, they shouldn't be trying
to access a compiler at all.


> > > Here is example with gtk-theme-e17lookalike http://paste.pocoo.org/show/388032/
> > > 
> > > And as side-note there is small problem when someone tries to hunt such
> > > checksum changes, because some tasks which are not directly using sstate
> > > like do_install do not save their run.* scripts in better place then
> > > ${WORKDIR}/temp 
> > > 
> > > So if your bitbake-diffsigs shows something like this:
> > > 
> > > Hash for dependent task
> > > /OE/shr-core/meta-shr/recipes-shr/shr/gtk-theme-e17lookalike_git.bb.do_install
> > > changed from 8a0de44f3f238f645eab9509172c2d8b to
> > > 9d6bf027c5f435498017a652088d7327
> > > 
> > > You need to find right ${WORKDIR} for that version, and there in temp
> > > directory right combination of run.do_install._pid_ scripts, but you
> > > don't know which _pid_ belongs to which sstate checksum and I guess pid
> > > cannot be stored in .siginfo because it would be always different.
> > 
> > Just for reference, if you want to generate two trees of all tasks
> > sigdata to compare you can do something like:
> > 
> > MACHINE=qemuarm bitbake console-image -S
> > MACHINE=qemux86 bitbake console-image -S
> > 
> > and then look at the tmpdir/stamps/*/* files using bitbake-diffsigs on
> > the files there to try and do this comparison more directly.
> 
> This works for multimachine build when I'm trying to find what's
> different between qemuarm and qemux86, but wont help if I'm trying to
> find what's changed in run.do_install from last week when I notice that
> some package is being rebuilt again.
> 
> Also already in bugzilla
> http://bugzilla.yoctoproject.org/show_bug.cgi?id=1074
> 
> > I'm open to other ideas to improving the way we write out the sigdata
> > pieces to make this kind of analysis easier...
> 
> I don't know sstate internals as you do, but cannot we store every
> dependant task used to count checksum in something like 
> state-gtk-theme-e17lookalike-all-oe-linux-gnueabi-0.1.1+gitr3+9b92a3d095ef1b53f55026cc292771d1507e6800-r8-all-2-do_install_8a0de44f3f238f645eab9509172c2d8b.gz
> and from second run
> state-gtk-theme-e17lookalike-all-oe-linux-gnueabi-0.1.1+gitr3+9b92a3d095ef1b53f55026cc292771d1507e6800-r8-all-2-do_install_9d6bf027c5f435498017a652088d7327.gz
> 
> or even flat filename structure like
> siginfo-do_install_8a0de44f3f238f645eab9509172c2d8b.gz and
> siginfo-do_install_9d6bf027c5f435498017a652088d7327.gz
> as hash collision is not very likely to happen and overwrites with same
> script are ok.
> 
> Then it would be easy to find actuall scripts which caused checksum
> change without ${WORKDIR}/temp files

How about:

http://git.yoctoproject.org/cgit.cgi/poky-contrib/commit/?h=rpurdie/allarch&id=aca23a2ab92ad950d44dd45524773591bc7993bc

which results in sigdata files in the stamp directory.

Cheers,

Richard