[rb-general] Reproducible Android apps: resources.arsc

[Torsten Grote]

Hi all,

when making Briar build reproducible, we encountered an issue with the
`resources.arsc` file inside the APK. This file holds compressed
resources and slightly differs when built on different machines, even if
a Docker container is used.

I submitted a bug report with Google now:

    https://issuetracker.google.com/issues/110237303

When inspecting the differences, apktool does not show anything. So when
using diffoscope only zipinfo shows a difference in the resources.arsc'
CRC value:

    https://code.briarproject.org/akwizgran/briar/-/jobs/1437

It would be nice, if more information would be provided here, but this
is probably a topic for apktool upstream, right?

We are aware of at least two other Android apps that are affected by
this problem. So far, we are working around the issue by using
disorderfs in stable sorting mode (which is unfortunately not available
in the version included in jessie-backports).

If anybody has other ideas for solving the issue, please let me know!

Kind Regards,
Torsten