Deltarpm xz problem with PPC generated rpms?

[Jonathan Dieter]

On Mon, Sep 14, 2009 at 1:35 PM, Dave Airlie <airlied at redhat.com> wrote:
> On Sun, 2009-09-13 at 19:43 +0300, Jonathan Dieter wrote:
>> Deltarpm seems to be unable to generate correct rpms for deltarpms
>> generated from noarch rpms.  The uncompressed payload is correct, but
>> the compressed xz payload is different.
>>
>> To test, using Rawhide's deltarpm, try running "applydeltarpm -r
>> anjuta-doc-2.27.3.0-3.fc12.noarch.rpm
>> anjuta-doc-2.27.3.0-3.fc12_2.27.92.0-1.fc12.noarch.drpm test.rpm".  You
>> should end up with an md5 mismatch.  If you rpm2cpio test.rpm, you'll
>> find that the uncompressed cpio archive is identical to that of
>> anjuta-doc-2.27.92.0-1.fc12.noarch.rpm.
>>
>> As I understand it, noarch rpms are generated on PPC builders.
>>
>> I suspect this problem is because of one of two reasons:
>> 1. The version of xz on the PPC builders is a different version than
>> that on the other builders?
>> 2. xz generates different compressed files when run on different
>> architectures
>>
>> If it is #2, this is a major problem (at least for yum-presto) because
>> the whole purpose of deltarpm is to regenerate the original (compressed)
>> rpm, given an older version and a deltarpm.  If we can't do that, the
>> regenerated package won't pass the signature check and will be
>> re-downloaded in full.
>>
>> I have access to i586 and x86_64 systems, but no PPC systems.  Could
>> someone either give me access to a PPC system or verify themselves
>> whether xz generates different files on different architectures (all
>> other things being equal).
>
> It doesn't.
> [airlied at pegasus ~]$ md5sum lm93_busted.o
> d7174fc439c4678927725d06de4f18a2  lm93_busted.o
> [airlied at pegasus ~]$ xz -z -c lm93_busted.o | md5sum
> 86dbb83fea5f4e2f77396b3f491a0cc1  -
>
> [airlied at ppcg5 ~]$ md5sum lm93_busted.o
> d7174fc439c4678927725d06de4f18a2  lm93_busted.o
> [airlied at ppcg5 ~]$ xz -z -c lm93_busted.o | md5sum
> acf84a6c173b040f6cf8ea96c7daa513  -
>
>
> thats just a random file I had on my machine here,
> first is x86 32-bit, second is ppc.
> xz-4.999.9-0.1.beta.fc12 on both.
>
> Dave.

That really really sucks.  Thanks for checking it for me.

Jonathan