[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: multiarch/bi-arch status (ETA) question

On Tue, Jul 05, 2005 at 02:12:13PM -0400, David Wood wrote:
> On Tue, 5 Jul 2005, Hugo Mills wrote:
> >  It caused considerable controversy when it was first suggested, and
> >continued to do so for some time. I suspect that the only reason it
> >isn't causing much controversy at the moment is because very few
> >people are doing anything on it right now, so it's not being noticed
> >much.
> I guess I can only ask... what... on... earth... was the problem?

   See below...

> It looks like an extremely small, well-calibrated change to me. Hold that 
> thought, I know what you're thinking...
> >  It's quite a lot more complicated than that. You need explicit
> >support in dpkg, for a start. And in dselect, apt, and all apt's
> >friends. I had a go at doing the dpkg support last year, and it
> >defeated me(*). It is very much non-trivial...
> Why? If I read this correctly...

   Well, let's say you want to install a 32-bit xine. That's written
in C, so you have to have a 32-bit glibc. So, you use dpkg to install
the 32-bit version of glibc2. But... you can't, because you already
*have* a package called glibc2 installed, which is the 64-bit version.

   A proposed solution of having "glibc2-64" and "glibc2-32" or
similar package names was rejected, because it would at least double
the archive storage requirements for multi-arch capable architectures.
The package manager changes are required to allow (e.g.) the glibc2
from the i386 architecture and the glibc2 from the amd64 architecture
to coexist, _despite having the same name_. dpkg from each
architecture would have a built-in list of the architectures which
could coexist.

> http://www.linuxbase.org/futures/ideas/multiarch/
> All the directories that get moved are symlinked from their original 
> locations. All you have to do is make the move, and then the apps; dpkg, 
> apt, etc all catch up _later_. That's all I'm suggesting. At some point 
> the infrastructure work is done and a big enough subset of packages are 
> ready, and you can switch. But in the meantime, why not start? At least 
> make a decision, move the directories...

   I'm not as familiar with the difficulties of porting libraries to
be multi-arch capable. You'll have to ask Tollef Fog Heen, who's done
the vast majority of the work on that side of it, IIRC.


=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
  PGP key: 1C335860 from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
   --- "It was half way to Rivendell when the drugs began to take ---    
              hold" - Hunter S Tolkien,  "Fear and Loathing              
                              in Barad D?r"                              

Attachment: signature.asc
Description: Digital signature

Reply to: