[poky] SSTATE builds more broken than I thought

[Tian, Kevin]

>From: Tian, Kevin
>Sent: Monday, November 15, 2010 9:14 AM
>
>I haven't got time looking into all of them. For random 3 (bzip2, gnome-vfs, webkit-gtk),
>they have the same symptom on populate_sysroot, e.g:
>
>basehash changed from c7c1d0c7ea052eef6f6665b8959b44fc to
>3eb4a010cbfb3b15df49d433f6593b0c
>Variable BB_TASKHASH value changed from 9e077b25e1e2c50d4f8a09a9356a6a6c to
>0d6608b425d8a59b21f5874b4914b412
>Hash for dependent task
>/home/poky/tasks/poky/meta/recipes-extended/bzip2/bzip2_1.0.5.bb.do_install changed
>from c4cba89fa491ecb0916a56f1e75c5f17 to c4e7f58c385e384749cc20ca1bd8fccf
>
>* basehash varies while no variable is explicitly listed by bitbake-diffsigs. I expected
>to see the variable causing difference to be marked explicitly here.
>* taskhash varies due to do_install, however bitbake-diffsigs doesn't list how do_install
>checksum is calculated. I made a quick comparison between run.do_install scripts, with
>major difference still on expanded variables. There may still have some whitelist work
>to be done.
>
>I used same source tree for two builds, which share same sstate-cache directory.
>

Another interesting thing. When I compare other prebuilt tasks, all the rest tasks
show the difference on task dependencies of do_install, which then results in the
taskhash difference. Take 'package' for example:

---

Tasks this task depends on changed from set

(['GLIBCTARGETOS', 'TARGET_VENDOR', 'FILE', 'PACKAGES', 'PR', 'PV', 'package_do_package', 'DEPLOY_DIR', 'PF', 'PE', 'PN', 'package_rpm_do_package', 'MULTIMACH_TARGET_SYS', 'D', 'TARGET_ARCH', 'TARGET_OS', 'TMPDIR', 'PKGD', 'WORKDIR', 'PACKAGEFUNCS', 'EXTENDPE', 'MULTIMACH_ARCH', 'PACKAGE_PREPROCESS_FUNCS'])

to set

(['GLIBCTARGETOS', 'TARGET_VENDOR', 'FILE', 'PACKAGES', 'PR', 'PV', 'package_do_package', 'DEPLOY_DIR', 'PF', 'PE', 'PN', 'package_rpm_do_package', 'MULTIMACH_TARGET_SYS', 'D', 'TARGET_ARCH', 'TARGET_OS', 'TMPDIR', 'PKGD', 'WORKDIR', 'PACKAGEFUNCS', 'EXTENDPE', 'MULTIMACH_ARCH', 'PACKAGE_PREPROCESS_FUNCS'])

Hash for dependent task /home/poky/tasks/poky/meta/recipes-extended/bzip2/bzip2_1.0.5.bb.do_install changed from c4cba89fa491ecb0916a56f1e75c5f17 to c4e7f58c385e384749cc20ca1bd8fccf

---

First, I carefully checked above dependency list, which show NO difference at all.

Second, you can see the taskhash values actually match my earlier post about
populate_sysroot prebuilts. However at that place no dep info is shown except 
the hashvalue change.

I'll try more to see whether it's consistent.

Thanks
Kevin