Re: [gentoo-dev] RFC: multilib and the compatibility to singlelib

[Mike Frysinger]

On Wednesday 21 October 2009 07:34:18 Michael Haubenwallner wrote:
> Mike Frysinger wrote:
> > On Tuesday 20 October 2009 09:06:29 Michael Haubenwallner wrote:
> >> As I'm building the toolchain myself too, I configure it with the
> >> 32bit host triplet on each platform, usually disabling multilib.
> >
> > this doesnt make any sense to me
>
> What exactly doesn't make sense to you:

it doesnt make sense to build your own toolchain when the default native one 
Gentoo provides includes all multilib support already.

but i guess when you're commercially developing a binary-only package, people 
tend to not have such freedoms as the binary-only mentality infects all 
layers.

> >> Isn't the intention of multilib to have a new (64bit) system
> >> be compatible with the corresponding old (32bit) system?
> >
> > your description of "compatible" is pretty vague.  ignoring /lib ->
> > /lib64 symlink (which shouldnt matter to any binaries), i'm not aware of
> > any differences off the top of my head.
>
> Well, "compatible" here means to me that when I do
> $ configure --{build,host}=i686-pc-linux-gnu

assuming you simply forgot the forcing of -m32 here, or you have a fully named 
i686-pc-linux-gnu-... toolchain

> on x86-linux, I'd like to expect this working on x86_64-linux too, as the
> "_64" can be seen as an "extension"[1] to x86 I just do not want to use.
>
> It turns out that it is the "/lib resolving to 64bit" thing only that
> causes me headaches here, which actually is distro-specific.

i'm not against changing things to fall in line with what other distros have 
settled on (guess that's the risk you take when you're one of the first 
distros to do multilib), i just want this kind of decision to be fully 
informed / thought out before making it.  it's not something i'd label 
"trivial".
-mike