From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxim Cournoyer Subject: bug#30756: GCC >= 6 '-isystem' and C_INCLUDE_PATH behavior changed, breaking Date: Sun, 19 Jan 2020 22:25:39 -0500 Message-ID: <87r1zulsgc.fsf@gmail.com> References: <87y2u3qh8b.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from eggs.gnu.org ([2001:470:142:3::10]:52695) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1itNiR-0007Wx-T3 for bug-guix@gnu.org; Sun, 19 Jan 2020 22:27:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1itNiQ-00087z-PQ for bug-guix@gnu.org; Sun, 19 Jan 2020 22:27:03 -0500 Received: from debbugs.gnu.org ([209.51.188.43]:38282) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1itNiQ-00087u-La for bug-guix@gnu.org; Sun, 19 Jan 2020 22:27:02 -0500 Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1itNiQ-00077B-It for bug-guix@gnu.org; Sun, 19 Jan 2020 22:27:02 -0500 Sender: "Debbugs-submit" Resent-Message-ID: In-Reply-To: <87y2u3qh8b.fsf@gnu.org> ("Ludovic \=\?utf-8\?Q\?Court\=C3\=A8s\=22'\?\= \=\?utf-8\?Q\?s\?\= message of "Sun, 19 Jan 2020 22:16:52 +0100") List-Id: Bug reports for GNU Guix List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-guix-bounces+gcggb-bug-guix=m.gmane-mx.org@gnu.org Sender: "bug-Guix" To: Ludovic =?UTF-8?Q?Court=C3=A8s?= Cc: reza.housseini@gmx.ch, 30756@debbugs.gnu.org, Reza Housseini Hello, Ludovic Court=C3=A8s writes: > Hi, > > Reza Housseini skribis: > >> So what is the workaround for this bug when one wants to use gcc >=3D 6.= 0.0 >> with a cmake build system? > > Guix has been using GCC 7.x as its default compiler for some time, and > everything works well, CMake or not. However, we also switched to using > =E2=80=98CPATH=E2=80=99 instead of =E2=80=98C_INCLUDE_PATH=E2=80=99 to wo= rk around this bug. > > HTH! > > Ludo=E2=80=99. As has been mentioned by Giel van Schijndel earlier in this bug report, using CPATH causes warnings to be emitted for core libraries such as glibc since the headers found in CPATH are not (rightfully) treated as system headers (and thus not muted by GCC). That has bitten me here, where I was mislead to think there was a build issue with the latest Inkscape: https://gitlab.com/inkscape/inkscape/issues/807. Many packages will end up having to disable warnings to cope with this behavior. It'd be nice to find a correct solution, but it seems I can't even make the build system of Inkscape work after switching from CPATH to CPLUS_INCLUDE_PATH and stripping it from any glibc/gcc include directories (I don't get the "stdlib.h: No such file or directory." error anymore, but I now get: "/gnu/store/zw5f5g5aqlxam3imaylfla0i98nkridf-glibc-2.30/include/bits/errno.= h:26:11: fatal error: linux/errno.h: No such file or directory" instead, which I don't understand). I also tried moving the glibc include directory to the end of CPLUS_INCLUDE_PATH and it would still wouldn't be happy. Hmmph! Maxim