From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id 6F161139694 for ; Wed, 26 Apr 2017 15:00:07 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 907A521C03E; Wed, 26 Apr 2017 14:59:57 +0000 (UTC) Received: from smtp.gentoo.org (mail.gentoo.org [IPv6:2001:470:ea4a:1:5054:ff:fec7:86e4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 48231E0BEE for ; Wed, 26 Apr 2017 14:59:56 +0000 (UTC) Received: from mail-io0-f171.google.com (mail-io0-f171.google.com [209.85.223.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: floppym) by smtp.gentoo.org (Postfix) with ESMTPSA id BF27733BEA7 for ; Wed, 26 Apr 2017 14:59:54 +0000 (UTC) Received: by mail-io0-f171.google.com with SMTP id r16so4360707ioi.2 for ; Wed, 26 Apr 2017 07:59:54 -0700 (PDT) X-Gm-Message-State: AN3rC/7elzDcHKdPt+1ztHXKaINvaAmdFCWu0jzCP87S9GxOh3PNci38 ZzXL0/9PLeJf8/mWnRL1lHdhoiVzVw== X-Received: by 10.107.160.77 with SMTP id j74mr204405ioe.58.1493218792878; Wed, 26 Apr 2017 07:59:52 -0700 (PDT) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-dev@lists.gentoo.org Reply-to: gentoo-dev@lists.gentoo.org MIME-Version: 1.0 Received: by 10.107.19.87 with HTTP; Wed, 26 Apr 2017 07:59:32 -0700 (PDT) In-Reply-To: <33941528.YhSZt8Px0E@pinacolada> References: <1492950948.19560.1.camel@gentoo.org> <1629949.a07gNpRjfP@pinacolada> <33941528.YhSZt8Px0E@pinacolada> From: Mike Gilbert Date: Wed, 26 Apr 2017 10:59:32 -0400 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [gentoo-dev] RFC: masking old versions of sys-devel/gcc To: Gentoo Dev Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Archives-Salt: 5ec31cce-758f-4372-8b1a-4d6493858273 X-Archives-Hash: 60b9a9f737707ab1d88c307b6af0f9b6 On Wed, Apr 26, 2017 at 5:32 AM, Andreas K. Huettel wrote: > Am Mittwoch, 26. April 2017, 02:37:17 CEST schrieb Francesco Riosa: >> 2017-04-26 0:26 GMT+02:00 Andreas K. Huettel : >> > Am Sonntag, 23. April 2017, 14:35:48 CEST schrieb Micha=C5=82 G=C3=B3r= ny: >> > > Hi, >> > > >> > > I'm thinking of masking old versions of sys-devel/gcc, in particular >> > > older than the 4.9 branch. >> > >> > Masking is fine; some time later (maybe in a few months) I'd even sugg= est >> > masking all of gcc-4. After all, unmasking them if you really need the= m is >> > rather easy. >> >> well if the intent is cleaning adding a package mask is just more burden= , >> not less. >> If they compile fine with the latest stable gcc better leave them unmask= ed, >> right? > > Except that "switching back" from gcc-5 to gcc-4 doesn't really work, and= that > gcc-4 will happily use gcc-5 libraries, with unintended consequences. What do you mean by "gcc-4 will happily use gcc-5 libraries"? If you mean at build time, it does NOT use gcc-5 libs. If it does, that's a= bug. % gcc-4.9.4 --print-search-dirs | grep ^libraries: libraries: =3D/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.4/:/usr/lib/gcc/x86_64-p= c-linux-gnu/4.9.4/../../../../x86_64-pc-linux-gnu/lib/x86_64-pc-linux-gnu/4= .9.4/:/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.4/../../../../x86_64-pc-linux-gn= u/lib/../lib64/:/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.4/../../../x86_64-pc-l= inux-gnu/4.9.4/:/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.4/../../../../lib64/:/= lib/x86_64-pc-linux-gnu/4.9.4/:/lib/../lib64/:/usr/lib/x86_64-pc-linux-gnu/= 4.9.4/:/usr/lib/../lib64/:/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.4/../../../.= ./x86_64-pc-linux-gnu/lib/:/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.4/../../../= :/lib/:/usr/lib/ If you mean runtime, that's controlled by /etc/ld.so.conf.d/05gcc-x86_64-pc-linux-gnu.conf. There's really nothing wrong with using a newer libstdc++ at runtime; they should be ABI compatible.