Re: Multiarch support (was Moving 32-bit libraries to (/usr)/lib32on amd64)

[Andreas Jochens <aj@andaco.de>]

Matthias Klose wrote:
> Bdale Garbee writes:
> > On Fri, 2006-02-24 at 01:12 +0100, Aurelien Jarno wrote:
> > 
> > > The only change planned is to make libc6-dev-i386 and libc6-i386 provide 
> > > a glibc on amd64 instead of ia32-libs. It will be in /emul/ia32-linux (I 
> > > still have to find how to do that cleanly in the debhelper files).
> > > 
> > > Bdale, do you agree with such a change?
> > > Yes, I think we can handle that.  It means some small work on ia32-libs
> > to stop delivering any conflicting files, but I'm sure we can work that
> > out easily enough.  If you want to provide me a patch for ia32-libs that
> > does what you want it to do, that would be welcome.
> 
> thanks.  with this setup we are able to build our toolchain without
> build dependencies on ia32-libs or with packages conflicting with
> future multiarch packages (maybe additionally building lib32z1 from
> zlib).

Hello,

please consider to install the 32-bit files from libc6(-dev)-i386, 
lib32gcc1, lib32stdc++ and lib32z1 in /usr/lib32 instead of 
/emul/ia32-linux/usr/lib.

This way the amd64 case would be handled in a similar way as the
other 32/64-bit "biarch" architectures.

I think that a future migration to multiarch will be easier if the amd64 
case needs no special handling. Also, with /usr/lib32 there will be no 
need for ugly glibc debhelper file hacks as it would be for 
/emul/ia32-linux/usr/lib.


I suggest the following setup for 32-bit libraries on amd64:

1. The ia32-libs package continues to install the 32-bit libraries in 
/emul/ia32-linux/usr/lib but it stops to provide the 32-bit libc6(-dev) 
packages.

2. The ia32-libs package does no longer provide a symlink from 
/usr/lib32 to /emul/ia32-linux/usr/lib.

3. The 32-bit libraries from libc6(-dev-)-i386, lib32gcc1, lib32stdc++, 
lib32z1 and other "_amd64.deb" packages are installed in 
/usr/lib32 which is not a symlink but a real directory.

4. The (/usr)/lib/i486-linux-gnu directories are reserved for future 
multiarch installations.


These changes could be implemented by simple patches without breaking
existing installations.

Regards
Andreas Jochens