Re: [gentoo-user] unexpected problems when switching c compilers

[Mickaël Bucas]

2016-10-25 20:02 GMT+02:00 Miroslav Rovis <miro.rovis@××××××××××××××.hr>:

> On 161025-12:02-0400, John Covici wrote:
> > Hi.  I finally decided to switch the c compiler from 4.9.3 to 5.3.0
> > and ran into some strange problems.  Although the kernel compiled
> > successfully, several packages in my last update of world got
> > undefined references, one of which was mktoolnix and also mpv.  Now I
> > did solve them by re-emerging the packages containing the references
> > and that fix things, although I had to do it in stages, getting past
> > one and finding another one.
> >
> > So, my question is, is there away to fix this throuought /usr/lib
> > without having to re-emerge world or something, or do I just wait and
> > take them one at a time during future updates?
> >
> > Thanks in advance for any suggestions.
>
> I've been using the 5.x since long months, since I'm on ~amd64. I
> remember vaguely there was an item in the eselect news about it, and
> links there and things. It should still be in your news list.
>

There was probably an Application Binary Interface change between the 2
compilers, for example [1]
The news from portage [2] explain how to use revdep-rebuild

All I know about these problems, I've learn from Diego Petteno's blog [3]
and the articles about Application Binary Interface
I've myself encountered this kind of problem even between minor versions of
GCC when the C++11 ABI was not stable.

I think you have some happy compiling ahead !

Best regards
Mickaël Bucas

[1] https://gcc.gnu.org/onlinedocs/libstdc%2B%2B/manual/using_dual_abi.html
[2]
https://www.gentoo.org/support/news-items/2015-10-22-gcc-5-new-c++11-abi.html
[3] https://blog.flameeyes.eu/2010/09/your-worst-enemy-undefined-symbols/