Re: [isar] reproducible build failures

[Jan Kiszka <jan.kiszka@siemens.com>]

Hi Venkata,

please avoid HTML emails on mailing lists.

On 03.09.21 17:19, Venkata.Pyla@toshiba-tsip.com wrote:
> Hi,
> 
> I am using isar system in isar-cip-core project [1] where I found some
> reproducible failures, which may be good to fix in the isar system.
> I am not good in modifying the isar system, so could you please guide me
> to fix these problems?
> 
> Here are the steps to check the reproducible failures in isar-cip-core
> project:
> https://gitlab.com/cip-project/cip-core/isar-cip-core/-/issues/12
> <https://gitlab.com/cip-project/cip-core/isar-cip-core/-/issues/12>
> https://gitlab.com/cip-project/cip-core/isar-cip-core/-/issues/13
> <https://gitlab.com/cip-project/cip-core/isar-cip-core/-/issues/13>
> 
> I also verified the reproducibility in the isar system and found similar
> failures that are copied below:
> ==============================================
> tmp/gpghomefHv8eRhk43/
> tmp/gpghomefHv8eRhk43/private-keys-v1.d/
> usr/share/doc/hello/changelog.Debian.gz
> var/cache/debconf/config.dat
> var/cache/debconf/config.dat-old
> var/cache/ldconfig/aux-cache
> var/lib/dpkg/info/enable-fsck.md5sums
> var/lib/dpkg/info/example-raw.md5sums
> var/lib/dpkg/info/hello.md5sums
> var/lib/dpkg/info/isar-disable-apt-cache.md5sums
> var/lib/dpkg/info/isar-exclude-docs.md5sums
> var/lib/dpkg/info/sshd-regen-keys.md5sums
> var/lib/initramfs-tools/4.19.0-17-amd64
> var/lib/systemd/catalog/database
> var/log/alternatives.log
> var/log/bootstrap.log
> var/log/dpkg.log
> var/log/apt/history.log
> var/log/apt/term.log
> ==============================================
> 
> Steps to check reproducible failures in isar
> ====================================
> $ . isar-init-build-env ../build1 && bitbake mc:qemuamd64-buster-tgz:isar-image-base
> $  . isar-init-build-env ../build2 && bitbake mc:qemuamd64-buster-tgz:isar-image-base
> $ mkdir -p rootfs1 rootfs2
> $ tar -xzvf ./build1/tmp/deploy/images/qemuamd64/isar-image-base-debian-buster-qemuamd64.tar.gz -C ./rootfs1/
> $ tar -xzvf ./build2/tmp/deploy/images/qemuamd64/isar-image-base-debian-buster-qemuamd64.tar.gz -C ./rootfs2/
> $ rsync -nrclv ./rootfs1/ ./rootfs2/ > difference.txt
> ====================================  
>  
> From the reproducible failures I found there are three different areas
> to fix these problem
> 1.       Changelog file generation, which is embedding the build time
> date value at here
> (https://github.com/ilbers/isar/blob/master/meta/classes/debianize.bbclass#L34
> <https://github.com/ilbers/isar/blob/master/meta/classes/debianize.bbclass#L34>
> )
> 2.       Log files generated by different application, which are adding
> build time values, I think we can remove these files if it is not
> required after build. ( I tried at here
> https://github.com/ilbers/isar/blob/master/meta/classes/image.bbclass#L183
> <https://github.com/ilbers/isar/blob/master/meta/classes/image.bbclass#L183>
> but it did not work)
> 3.       Cache and temporary files, I think we can delete these files also.
> 
> Please guide me to fix these issues.
> 

Did you also cross-check what
https://wiki.debian.org/ReproducibleInstalls suggests?

Then maybe start with the [isar-]bootstrap. Hook into
https://github.com/ilbers/isar/blob/03124cca669f50b682336a0bdf4ede5a4238e144/meta/recipes-core/isar-bootstrap/isar-bootstrap.inc#L232
to perform cleanups.

Using SOURCE_DATE_EPOCH as control over timestamps might be an interface
worth to explore.

Jan

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