Bug#766708: Processed: Re: Bug#766708: breaks multiarch cross building

[Helmut Grohne <helmut@subdivi.de>]

On Sat, Nov 22, 2014 at 08:37:56PM +0000, Dimitri John Ledkov wrote:
> gcc:
> (wheezy) http://sources.debian.net/src/gcc-4.7/4.7.2-5/debian/README.cross/
> (jessie) http://sources.debian.net/src/gcc-4.8/4.8.3-13/debian/README.cross/
> 
> Fundamentally the standard way to build cross-compilers from debian
> sources remained the same and is not broken in any way.
> The documentation has existed, and still exists, and is still supported...

Thanks for pointing this out. When I started cross building, I briefly
looked at these and immediately skipped them, because they looked way
out of date. I'm sorry, if this decision was flawed.

I'm not sure why you refer to gcc-4.8 as the jessie compiler when most
of the archive is built with gcc-4.9. I assume that this is a mistake
and will correct the url to
http://sources.debian.net/src/gcc-4.9/4.9.2-2/debian/README.cross/.

So let me reexamine:

 * emdebian refers to squeeze toolchains.
 * "http://zigzag.lvk.cs.msu.su/~nikita/debian/"; The domain name no
   longer exists.
 * Then it mysteriously talks about a "toolchain-source" approach I've
   never heard off and refers to gcc versions between 3.3 and 4.3. I
   guess I can skip this part as it feels more like a history lesson.
 * In section 1.3 it tells me that I need to download a libc for my
   target. So at least bootstraps appear to be unsupported by the
   default method (according to the documentation).
 * Section 2 explains to build cross compilers by setting GCC_TARGET.
   As of dpkg version 1.17.17 this variable is no longer honoured. What
   is being built here is a native compiler.

My conclusion is that the reference to this documentation is a straw
man. The process described therein does not cover relevant cases and
does not work either. On the other hand, the unsupported method has been
working for me.

I'd be happy to help fixing this, but I lack an understanding of how the
default method is supposed to work. So I think I've done what I can do
by pointing out what is wrong. Should I open a bug against gcc-4.9?

Dimitri, it seems to me that your perception of reality is skewed. Your
assuming that the default method was working for everyone does not match
my reading of this bug log. I have the impression that you are trying to
deny the usefulness of the alternate method. It feels roughly equivalent
to (hypothetical) systemd proponents denying the usefulness of sysvinit
by arguing that sysvinit is broken while at the same time it works for
many. It is my understanding that we don't intentionally break stuff
unless there is reason to do so. Please, can we rather work on making
the default work for everyone and keep the non-default available until a
significant amount of users is able to switch?

Helmut