bug#27563: [PATCH v3 0/2] Make ghostscript reproducible.

[ludo@gnu.org (Ludovic Courtès)]

Danny Milosavljevic <dannym@scratchpost.org> skribis:

> Hi Ludo,
>
> On Fri, 07 Jul 2017 14:00:09 +0200
> ludo@gnu.org (Ludovic Courtès) wrote:
>
>> Danny Milosavljevic <dannym@scratchpost.org> skribis:
>> 
>> > Also, newer PDF files have an RDF header specifying some extra information
>> > in an XML-like format.  For example there's an instance UUID (PDF/A specifies
>> > that it's recommended to set this to an empty string), and a document UUID.
>> > The latter again is time-based.  
>> 
>> If it’s time-based, then the solution may be to honor SOURCE_DATE_EPOCH.
>
> Upstream says definitely not.  The UUIDs are supposed to be unique and they don't want anyone writing fixed UUIDs into documents (except for "" for the instance ID which they themselves do).
>
> I think there could be some enterprise search engine which associates a document with other resources using the document UUID - and if everyone went and reused UUIDs it would be very confused.
>
> That's why I left it off.

OK, makes sense.  Maybe we can still have it disabled (or enabled) by
environment variable instead of having it removed wholesale?

Ludo’.