Re: [gentoo-user] Re: Gcc 5.3

[lee <lee@yagibdah.de>]

Paul Colquhoun <paulcol@andor.dropbear.id.au> writes:

> On Wed, 30 Dec 2015 17:32:44 lee wrote:
>> Neil Bothwick <neil@digimed.co.uk> writes:
>> > On Tue, 29 Dec 2015 19:21:01 +0100, lee wrote:

> [...]
>> >> So if I'd never explicitly update everything but run emerge --sync
>> >> frequently, things would be updated over time, occasionally?
>> > 
>> > No, nothing would get updated. To do that you need to run emerge @world
>> > after emerge --sync.
>> 
>> Well, yes, but what if want to install a package that hasn't been
>> installed yet, or re-emerge an installed package with different USE
>> flags, after updating the portage tree?  Will a more recent version be
>> installed than would have been installed before the tree was updated,
>> maybe updating other packages to more recent versions because they are
>> needed for the new package?
>
>
> You have a couple of options.
>
> First, start with "emerge -p whatever" and see what update would happen with 
> no adjustments.
>
> Then try again, but specify the version you want and see if that works: 
> "emerge -p =whatever-1.2.3"
>
> If it is still trying to install updated versions of libraries or other 
> dependencies, make a file like /etc/portage/package.mask/whatever and block 
> anything higher than the library/dependency versions you already have.
>
> A bit more work, but probably not much.
>
> However, if you get too far behind, the versions you want may have been 
> removed from the portage tree. This is still not a deal breaker. Old ebuilds 
> are available from the Gentoo attic at https://sources.gentoo.org/cgi-bin/viewvc.cgi and can be installed in a local overlay. (I put mine in 
> /usr/local/portage). Just put "PORTDIR_OVERLAY=/usr/local/portage" into 
> /etc/portage/make/conf and you should be set.
>
> You could also use the local overlay to just add the updated ebuilds for 
> things you do want to upgrade (and required dependency upgrades, etc) but I 
> think that would quickly become very unwieldy.

Thank you for the explanation.

I've installed gcc 5.2.0 and am running into trouble when trying to
compile the test application.  That just won't work.

It also runs out of memory too easily.

OTOH, I've compiled a kernel with it (unless the compilation somehow
picks a different version automatically), and it works fine.

>> > Exactly, run gcc-config, compile/emerge the program, run gcc-config again.
>> 
>> And what about ccache?  Will it use the new version automatically and
>> detect that the compiler version has changed so that files in the cache
>> need to be recompiled?

To answer my own question:  That also works without any further ado.