Am Mittwoch, 6. Dezember 2017, 08:00:40 CET schrieb Raffaele Belardi:
> One (~x86) LXDE system completed the switch with no problem, the other
> (~amd64) built all except two packaged (sdlmame and torcs) which did not
> build with gcc-7.2 even before the switch to 17.0.
> 
> Gentoo devs and arch testers did a good job as usual.
> 
> I'll do the switch on the Gnome system in the next days but up to now I can
> say that the switch to 17.0 is a _lot_ less painful than switching major
> compiler version.
> 
> raffaele

I'll add my support for this, the migration was almost completely painless on 
all three of my systems.  There were only a few exceptions:

- I hit the aforementioned cdrdao failure (which I opted to solve via USE 
flag).

- On my laptop I hit the ICU incompatibility with qtwebengine because I had 
firefox install with USE="system-icu" (which was masked at some point in the 
13.0 profiles, which is why I didn't hit this until now), so I unset the USE 
flag again, but that caused some post-migration emerging, which was annoying, 
but not horrible.

- On my desktop rust failed for some reason (almost at the end, of course, 
when building rustdoc), but simply emerging it again afterwards worked.

- On my desktop I also hit the mupen64plus-ui-console build failure.

Note that all of these have open bugs (except for the rust one, but I expect 
that simply came from an inconsistency due to the unfinished "emerge -e 
@world", or a random bitflip, or something similarly ephemeral).

(Oh, and libsidplay failed because its maintainer is apparently too busy to 
fix its incompatibility with app-shells/dash, but that had nothing to do with 
the migration per se.)

I'll also add -- not because I was worried about it but because the 
possibility was mentioned in another thread -- that I can't say I'm noticing 
any performance hits, even on my 11 year old Athlon64 X2.  (IIUC, per the GCC 
manual, PIC and PIE only affect startup time, not runtime, so this result 
should be expected.)

-- 
Marc Joliet
--
"People who think they know everything really annoy those of us who know we
don't" - Bjarne Stroustrup