Three bytes in a zip file

[Chris Lamb]

Hey Fay,

> The original reproducibility issue this thread started with was traced back to
> the atime back then, my tool just hopefully makes doing that a bit easier :)

Oh! I somehow missed that this was an atime-related issue at the time…
in addition to missing your PoC to call out to repro-apk from diffoscope
as well. Sorry about both of those.

Learning that it was an atime issue was especially interesting as it
connected a few things in my head, including the fact that I could
never reproduce a few .zip-related issues in the past — which I now
realise is because I mount my filesystems with noatime.

I'll implement zipdetails support shortly. As you say, it will be
quicker/straightforward to integrate. :)

Chris




> I almost forgot: zipdetails (that comes with perl) can also show this difference
> (and quite a lot of other things, though its output is not usually so easy to
> diff which is why I tend to prefer my own tools -- diff-zip-meta, zipinfo.py,
> apksigtool -- but it might be easier to use that for diffoscope, at least for
> now):
>
> $ diff -Naur <( zipdetails atime1.zip ) <( zipdetails atime2.zip )
> @@ -15,7 +15,7 @@
>  0023   Length              0009
>  0025   Flags               '03 mod access'
>  0026   Mod Time            65EB87EA 'Fri Mar  8 22:49:30 2024'
> -002A   Access Time         65EB87EA 'Fri Mar  8 22:49:30 2024'
> +002A   Access Time         65EB87EE 'Fri Mar  8 22:49:34 2024'
>  002E Extra ID #0002        7875 'ux: Unix Extra Type 3'
>  0030   Length              000B
>  0032   Version             01

-- 
      o
    ⬋   ⬊      Chris Lamb
   o     o     reproducible-builds.org 💠
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