[Pkg-phototools-devel] Bug#682980: darktable: should use system shared libraw

[Jonas Smedegaard]

[switching to non-quiet flavor of bug address]

On 12-07-28 at 12:09pm, Pascal de Bruijn wrote:
> On Sat, Jul 28, 2012 at 2:26 AM, Jonas Smedegaard <dr at jones.dk> wrote:
> > On 12-07-28 at 12:42am, Pascal de Bruijn wrote:
> >> On Sat, Jul 28, 2012 at 12:28 AM, Jonas Smedegaard <dr at jones.dk> 
> >> wrote:
> >> > On 12-07-27 at 10:08pm, Pascal de Bruijn wrote:
> >> >> When Darktable is linked against an external Libraw (or for that 
> >> >> matter RawSpeed) library, we likely would get lots of camera 
> >> >> support bugs which aren't reproducible (assuming the Debian 
> >> >> Libraw version is older), wasting our time. Or we aren't getting 
> >> >> any valid camera support bugs reported (assuming the Debian 
> >> >> Libraw version is newer). So both cases (newer and older) are 
> >> >> detrimental to our project.
> >> >
> >> > Bugs from users of Debian should go to Debian for this exact 
> >> > reason: The Debian package maintainers should pass upstream to 
> >> > you the Darktable developers only bugs relevant for you.
> >>
> >> Yeah, but that's not reality. People will just come and ask on our 
> >> mailing lists and irc channels, often not telling us they are 
> >> running Debian (unless we specifically ask), wasting our time.
> >
> > I recognize that issue from users of Debian reporting bugs about 
> > packages derived from Debian but changed in various ways unknown to 
> > us.
> >
> > What I do with that is not try enforce one single use of the 
> > packages we provide, but a) tell our users that they are free to use 
> > Debian also in (to us) weird ways (that's one of the freedoms that 
> > DFSG-free licensing provides!), but b) they are strongly recommended 
> > to tell us very clearly up front when reporting bugs if their setup 
> > of Debian is unusual, to not waste our time e.g. chasing bugs 
> > inefficiently.
> 
> I guess that's a similar issue.
> 
> However, there is a difference with users personally modifying things. 
> And distributions shipping non-standard versions.
> 
> We'd like to make sure that users get a user experience that is 
> representative of our intended Darktable user experience.

Users of Debian are not only personal.  One user of Debian is the 
distribution Ubuntu.


> >> >> So in my opinion Darktable should get a permanent exception to 
> >> >> this Debian policy.
> >> >>
> >> >> PS: Please don't misunderstand, I generally agree with the 
> >> >> policy in this regard, it's just that it makes very little sense 
> >> >> for projects like Darktable.
> >> >
> >> > Sorry, but I fail to see how this issue is any different from 
> >> > e.g. consumers of libexiv and the resulting changes to richness 
> >> > of the EXIF
> >>
> >> Having an older libexiv2 will not prevent files from being read at 
> >> all. Having an old libraw could result in images being "green" 
> >> instead of properly white balanced in some cases. And in even fewer 
> >> cases it could result in files not loading at all (where they 
> >> should have just loaded just fine (and/or not being green) with 
> >> unpatched darktable sources).
> >>
> >> > data supported with various versions of that library: as long as 
> >> > the API is the same, newest version of the library most often is 
> >> > preferred.
> >>
> >> Yes, but that isn't what happens in reality. What happens in 
> >> reality is that Debian is usually behind, really...
> >>
> >> > If I misunderstood and there is really something more intimate 
> >> > going on specifically with Darktable and its libraries could you 
> >> > please try elaborate more on that?
> >>
> >> With regard to the patch, LibRaw does RAW reading _and_ processing, 
> >> we only use the RAW reading bits (which is fairly atypical). But 
> >> the LibRaw processing bits don't support float DNGs (which we use 
> >> for HDR IIRC), so the LibRaw authors are blocking them from being 
> >> read. So we need to patch that up for our particular use.
> >>
> >> Besides the above, there is nothing more intimate going on, except 
> >> that I see lots of potential problems, with little or no gain at 
> >> all in our particular case.
> >
> > Thanks for the details.
> >
> > It still sound to me like Darktable would make good sense to link 
> > against shared libraries for Debian.
> 
> I don't see how you'd resolve the float issue. But even if that were 
> to be resolved. What is the perceived benefit in this particular case?

Same benefits as with other cases.  This is nicely described in Debian 
Policy: http://www.debian.org/doc/debian-policy/footnotes.html#f30


Regards,

 - Jonas

-- 
 * Jonas Smedegaard - idealist & Internet-arkitekt
 * Tlf.: +45 40843136  Website: http://dr.jones.dk/

 [x] quote me freely  [ ] ask before reusing  [ ] keep private
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