Re: [gentoo-user] coexisting GCC versions

[Alan McKinnon]

On Sunday 28 June 2009 05:47:23 Volker Armin Hemmann wrote:
> On Sonntag 28 Juni 2009, Alex Schuster wrote:
> > Volker Armin Hemmann writes:
> > > On Sonntag 28 Juni 2009, Alex Schuster wrote:
> > >> Or keep 4.3 as default, I don't think you could run into problems.
> > >
> > > he will over time. If you switch default compiler emerge -s world has
> > > to be done.
> >
> > According to Alan McKinnon's (and my own experience), this is not
> > necessary, unless there are ABI changes. But there were none between 4.1
> > and 4.3.
> >
> > http://www.mail-archive.com/gentoo-user@l.g.o/msg83724.html
> >
> >         Wonko
>
> you don't have to compile between 4.2.0 and 4.2.1 - sure.
>
> But with 4.2 to 4.3 I only got a stable system after compiling everything
> with the same compiler. So whatever Alan says - I know how borked my box
> was with half of the libs compiled by one compiler and the rest by the
> other.

That's interesting. I run ~amd64 here and update almost daily - so I got 
practically every gcc version that hit the tree since 3.3 at some stage. And I 
never had the problem you describe.

It's likely that you have a set of libs that indeed *are* sensitive to 
different gcc versions, and I'm not using those libs (so I don't get the 
problems).

I wonder if it would be worth the effort to investigate this further and 
isolate problem packages. It seems that only Gentoo (and derivs) have this 
problem - binary distros rebuild everything from scratch with each new 
releases (equivalent to emerge -e world) so they tend to never run into these 
issues.

-- 
alan dot mckinnon at gmail dot com