From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?UTF-8?Q?Court=C3=A8s?=)
Subject: bug#19973: Grafts break debug outputs
Date: Tue, 07 Mar 2017 22:54:39 +0100
Message-ID: <87a88wrbvk.fsf@gnu.org>
References: <878ufh71do.fsf@netris.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Return-path: <bug-guix-bounces+gcggb-bug-guix=m.gmane.org@gnu.org>
Received: from eggs.gnu.org ([2001:4830:134:3::10]:38825)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <Debian-debbugs@debbugs.gnu.org>) id 1clN4U-0003vE-Q9
	for bug-guix@gnu.org; Tue, 07 Mar 2017 16:55:07 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <Debian-debbugs@debbugs.gnu.org>) id 1clN4Q-0004E1-6c
	for bug-guix@gnu.org; Tue, 07 Mar 2017 16:55:06 -0500
Received: from debbugs.gnu.org ([208.118.235.43]:46919)
	by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16)
	(Exim 4.71) (envelope-from <Debian-debbugs@debbugs.gnu.org>)
	id 1clN4Q-0004Dv-3G
	for bug-guix@gnu.org; Tue, 07 Mar 2017 16:55:02 -0500
Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2)
	(envelope-from <Debian-debbugs@debbugs.gnu.org>) id 1clN4P-0006rz-SE
	for bug-guix@gnu.org; Tue, 07 Mar 2017 16:55:01 -0500
Sender: "Debbugs-submit" <debbugs-submit-bounces@debbugs.gnu.org>
Resent-Message-ID: <handler.19973.B19973.148892369426390@debbugs.gnu.org>
In-Reply-To: <878ufh71do.fsf@netris.org> (Mark H. Weaver's message of "Sun, 01
	Mar 2015 00:06:11 -0500")
List-Id: Bug reports for GNU Guix <bug-guix.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/bug-guix>,
	<mailto:bug-guix-request@gnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/archive/html/bug-guix/>
List-Post: <mailto:bug-guix@gnu.org>
List-Help: <mailto:bug-guix-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/bug-guix>,
	<mailto:bug-guix-request@gnu.org?subject=subscribe>
Errors-To: bug-guix-bounces+gcggb-bug-guix=m.gmane.org@gnu.org
Sender: "bug-Guix" <bug-guix-bounces+gcggb-bug-guix=m.gmane.org@gnu.org>
To: Mark H Weaver <mhw@netris.org>
Cc: 19973@debbugs.gnu.org

Mark H Weaver <mhw@netris.org> skribis:

> mhw@jojen:~$ guix build guile
> guix build: warning: ambiguous package specification `guile'
> guix build: warning: choosing guile-2.0.11 from gnu/packages/guile.scm:11=
0:2
> /gnu/store/3lhr8q28q6f59774di9av7ncy09jd55d-guile-2.0.11
> /gnu/store/rgv3fvy6xqp6966rfh8v6fv7m48abcbh-guile-2.0.11-debug
> mhw@jojen:~$ guix package -I guile
> guile	2.0.11	out	/gnu/store/3lhr8q28q6f59774di9av7ncy09jd55d-guile-2.0.11
> guile	2.0.11	debug	/gnu/store/rgv3fvy6xqp6966rfh8v6fv7m48abcbh-guile-2.0.=
11-debug
> mhw@jojen:~$ ls -l .guix-profile/lib/debug/gnu/store/
> total 8
> lrwxrwxrwx 12 root guixbuild 128 Dec 31  1969 122jv790mv2mlnylbrbzav65vgh=
bw93n-guile-2.0.11 -> /gnu/store/rgv3fvy6xqp6966rfh8v6fv7m48abcbh-guile-2.0=
.11-debug/lib/debug/gnu/store/122jv790mv2mlnylbrbzav65vghbw93n-guile-2.0.11
> lrwxrwxrwx 15 root guixbuild 127 Dec 31  1969 3g20rdmnavpblsmgppyl8jhg67n=
idhjk-glibc-2.20 -> /gnu/store/hrny2whqg9c3m0klyfpbmmcyiir9yf8m-gcc-toolcha=
in-4.9.2/lib/debug/gnu/store/3g20rdmnavpblsmgppyl8jhg67nidhjk-glibc-2.20
>
> I guess GDB can't find the debugging information because
> 122jv790mv2mlnylbrbzav65vghbw93n-guile-2.0.11 is the name of the guile
> directory *before* grafting.

I wonder if the problem you described here still exists today.

However, one very likely problem is that .debug files include a CRC of
the binary they correspond to (info "(gdb) Separate Debug Files"), and
that CRC is not updated when we graft things.

We could change our grafting code to specifically address this problem
(using (guix elf) & co.).

Similar issue with build IDs: <https://bugs.gnu.org/25752>.

Ludo=E2=80=99.