Re: [RFC] getting rid of the config.guess/sub problem when bootstrapping new ports/systems

[Ralf Corsepius]

On 05/15/2013 05:53 AM, Mike Frysinger wrote:
> On Monday 08 October 2012 08:46:57 Paul Wise wrote:
> > So, Debian is in the process of bringing up our upcoming arm64 port.
> > Unfortunately we are also coming across lots of packages with rather
> > outdated config.guess and config.sub files (see links below). We could
> > patch every single package that contains config.guess and config.sub but
> > that would be a lot of effort that doesn't scale. We could also patch
> > our build tools but the problem would still exist for other distros.
>
> yes, Gentoo fixed this for every package in our tree like 9 years ago (we added
> a common function like 11 years ago that ebuilds could call manually, but we
> found that didn't scale).  when you run a standard autoconf script, we
> automatically search for files named "config.sub" and "config.guess" and replace
> them with the up-to-date host copy.  no checking or anything :).  in
> hindsight, that seems like a bad idea, but in practice, i think we have yet to
> find a package that this doesn't actually work.
Well, I can't imagine a case affecting config.guess, but constructing 
cases affecting config.sub is pretty simple.

Classical use-case is developing on cross-built packages, which require 
a new host/target-tuple and therefore ship a customized/modified config.sub.

Those cases are rare in publicly available/released packages, but they 
are not uncommon in the toolchain/OS developer's community. Think about 
working on "cfin-MikeOS" toolchain in binutils/gcc/gdb or adding support 
for it to other auto*tools-based package ;)

At least for RTEMS, we had once carried such a customized config.sub for 
a short period time.

Ralf