Received: (at 66268) by debbugs.gnu.org; 26 Nov 2024 18:37:04 +0000
From debbugs-submit-bounces <at> debbugs.gnu.org Tue Nov 26 13:37:04 2024
Received: from localhost ([127.0.0.1]:52381 helo=debbugs.gnu.org)
by debbugs.gnu.org with esmtp (Exim 4.84_2)
(envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>)
id 1tG0Qp-00019A-I2
for submit <at> debbugs.gnu.org; Tue, 26 Nov 2024 13:37:04 -0500
Received: from cyberdimension.org ([79.143.250.36]:49630
helo=rockpro64.cyberdimension.org)
by debbugs.gnu.org with esmtp (Exim 4.84_2)
(envelope-from <GNUtoo@HIDDEN>) id 1tG0Qn-00018Y-0h
for 66268 <at> debbugs.gnu.org; Tue, 26 Nov 2024 13:37:02 -0500
DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; s=dkim; bh=kijp9KIiyVNIjrZ
fT5yghVEWx916TC0g6hP/I9aeNJ4=; h=subject:to:from:date;
d=cyberdimension.org; b=Duk7rMRXPyQZV/v8Cn+fZXV0WM476FJMjj4bQl/W/by1fM
oLLJliT1sb17sbpoNFYLvO7SV40LxG0I+279duiM7a1U+LPpLrDf2S8CBNdfGWk9UuaUBb
NQPRmikgjnZErohr/1NRCPIOWaIDk3grCzNx1qvA7ZX6p5dIGS0KY+Bx8LumY6/vyzWS98
Kiolv1alEabKAjAm8pITzXdR+bAXkTbJ2zgPfJYLIhKESRKlY1QQnDK8cdIweCCz/5du6u
DP/fNTrJ7ENdliu2b3NCvi85yVI4RNMaUlI8x0IfUEo5Kc0ASHnyXHigo0FHITjJzckR7N
p6WUbuvBN/Y3+07w==
Received: from primary_laptop (localhost [127.0.0.1])
by rockpro64.cyberdimension.org (OpenSMTPD) with ESMTP id 60ee59d5;
Tue, 26 Nov 2024 18:36:57 +0000 (UTC)
Date: Tue, 26 Nov 2024 19:15:08 +0100
From: Denis 'GNUtoo' Carikli <GNUtoo@HIDDEN>
To: 66268 <at> debbugs.gnu.org, Adrien 'neox' Bourmault <neox@HIDDEN>, Jason
Self <j@HIDDEN>
Subject: Re: Guix makes invalid assumptions regarding guile-git guarantees
leading to guix pull failing
Message-ID: <20241126191508.3145f604@primary_laptop>
X-Mailer: Claws Mail 4.3.0 (GTK 3.24.41; x86_64-pc-linux-gnu)
MIME-Version: 1.0
Content-Type: multipart/signed; boundary="Sig_/9e5roTwbQ3=qYDStw0=yZsk";
protocol="application/pgp-signature"; micalg=pgp-sha256
X-Spam-Score: 0.0 (/)
X-Debbugs-Envelope-To: 66268
X-BeenThere: debbugs-submit <at> debbugs.gnu.org
X-Mailman-Version: 2.1.18
Precedence: list
List-Id: <debbugs-submit.debbugs.gnu.org>
List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>,
<mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe>
List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/>
List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org>
List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help>
List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>,
<mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe>
Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org
Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org>
X-Spam-Score: -1.0 (-)
--Sig_/9e5roTwbQ3=qYDStw0=yZsk
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: quoted-printable
Hi,
I've found a much smaller test case:
> git clone https://git.savannah.gnu.org/git/gnuboot.git
> cd gnuboot
> guix git authenticate \
> bf2b91df54aa71ecbfab891d32000ad2d6af6093 \
> "E23C 26A5 DEEE C5FA 9CDD D57A 57BC 26A3 6871 16F6" \
> -k origin/keyring
The repository only consists of 683 commits for now.
The commit that is problematic is precisely the introduction commit
(bf2b91d). There are bigger commits messages in the history before that
but it seems not to be an issue.
A workaround I found is to substitute the commit bf2b91d ("Add
.guix-authorizations file for "guix git authenticate".") with the one
right after it (dde4223 Fix .guix-authorizations for Denis 'GNUtoo'
Carikli.).
So while this bug needs fixing, we are also looking for a workaround as
once a fix lands upstream, it could take some time to reach everybody
especially because we'd like to make guix git authenticate work, with
the guix packages from various distributions (PureOS has Guix 1.2),
without requiring to do a git pull which can probably take hours.
If I understood right, the workaround explained above is not sufficient
as at any time, pushing commits could break guix git authenticate, so
I'm also looking for a reliable way to avoid the condition that makes
guix git authenticate fail.
So I see 2 approaches, one is to write code that looks at the size of
commits, I've done that but then we can't easily reproduce the issues
if we use the commit right after bf2b91d. I've added big commits after
that.=20
I've now started to
rebase https://git.sr.ht/~graywolf/guix-guile-git-repro on top of some=20
commits in another repository that adds a .guix-authorizations file but
it will take between 24h and 48h to rebase on a VM on a D16 on tmpfs, so
it's not very practical for the tests.
Another way could be to remove the authentication setup with some code
like that:
> cp -f config .git/config
> rm -f .git/hooks/post-merge
> rm -f .git/hooks/pre-push
and then run the guix git authenticate command but I'm unsure if this
could have false negative and let through commit that break everything
when people clone the repository and run guix git authenticate for the
first time.
Also did other people encounter this issue in other git repositories?
This could also help with testing.
Denis.
--Sig_/9e5roTwbQ3=qYDStw0=yZsk
Content-Type: application/pgp-signature
Content-Description: OpenPGP digital signature
-----BEGIN PGP SIGNATURE-----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=F0ny
-----END PGP SIGNATURE-----
--Sig_/9e5roTwbQ3=qYDStw0=yZsk--
bug-guix@HIDDEN:bug#66268; Package guix.
Full text available.Tomas Volf <~@wolfsden.cz>
to control <at> debbugs.gnu.org.
Full text available.
Received: (at 66268) by debbugs.gnu.org; 2 Oct 2023 20:55:18 +0000
From debbugs-submit-bounces <at> debbugs.gnu.org Mon Oct 02 16:55:17 2023
Received: from localhost ([127.0.0.1]:38133 helo=debbugs.gnu.org)
by debbugs.gnu.org with esmtp (Exim 4.84_2)
(envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>)
id 1qnPwg-0007TR-5Z
for submit <at> debbugs.gnu.org; Mon, 02 Oct 2023 16:55:17 -0400
Received: from wolfsden.cz ([37.205.8.62]:59470)
by debbugs.gnu.org with esmtp (Exim 4.84_2)
(envelope-from <ws@HIDDEN>) id 1qnPwa-0007T6-0Q
for 66268 <at> debbugs.gnu.org; Mon, 02 Oct 2023 16:55:12 -0400
Received: by wolfsden.cz (Postfix, from userid 104)
id 17E7B25FC39; Mon, 2 Oct 2023 20:54:49 +0000 (UTC)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=wolfsden.cz; s=mail;
t=1696280089; bh=kTWQvTZK5SmlTRtauP524+hZlPFvlyK6lDSnQkcAiUY=;
h=Date:From:To:Cc:Subject:References:In-Reply-To;
b=qBFHDW5D3STZO6OIO8z8hI4+P5OcyPxkJd6tIEEfjtr5h4/w9OYAJ+zRQzWjJqW0b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X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on wolfsden
X-Spam-Level:
X-Spam-Status: No, score=-0.8 required=5.0 tests=ALL_TRUSTED,DKIM_SIGNED,
DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,URIBL_BLOCKED
autolearn=no autolearn_force=no version=3.4.6
Received: from localhost (unknown [193.32.127.157])
by wolfsden.cz (Postfix) with ESMTPSA id E17F4261A5A;
Mon, 2 Oct 2023 20:54:44 +0000 (UTC)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=wolfsden.cz; s=mail;
t=1696280085; bh=kTWQvTZK5SmlTRtauP524+hZlPFvlyK6lDSnQkcAiUY=;
h=Date:From:To:Cc:Subject:References:In-Reply-To;
b=rvKbjNiKtX1Obw4WQKdiRHW5UmD5qZodCFqlVFokjSQ/mtyaQ7XKz62ei2kgjqfbH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Received: from localhost (localhost [local])
by localhost (OpenSMTPD) with ESMTPA id 7d3bde05;
Mon, 2 Oct 2023 20:54:44 +0000 (UTC)
Date: Mon, 2 Oct 2023 22:54:44 +0200
From: wolf <wolf@HIDDEN>
To: Simon Tournier <zimon.toutoune@HIDDEN>
Subject: Re: bug#66268: Guix makes invalid assumptions regarding guile-git
guarantees leading to guix pull failing
Message-ID: <ZRsuFGEjxymdIK92@ws>
References: <ZRcA23RUYvBuE1JX@ws>
<86fs2vek60.fsf@HIDDEN>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
protocol="application/pgp-signature"; boundary="+UQ01KY/FuPcIZvY"
Content-Disposition: inline
In-Reply-To: <86fs2vek60.fsf@HIDDEN>
X-Spam-Score: 0.2 (/)
X-Debbugs-Envelope-To: 66268
Cc: 66268 <at> debbugs.gnu.org
X-BeenThere: debbugs-submit <at> debbugs.gnu.org
X-Mailman-Version: 2.1.18
Precedence: list
List-Id: <debbugs-submit.debbugs.gnu.org>
List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>,
<mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe>
List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/>
List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org>
List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help>
List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>,
<mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe>
Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org
Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org>
X-Spam-Score: -0.8 (/)
--+UQ01KY/FuPcIZvY
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
On 2023-09-30 17:48:55 +0200, Simon Tournier wrote:
> Hi,
>=20
> Hum, the updates seem:
>=20
> + libgit2 on Feb 17 2023,
> + guile-git on May 15 2022.
>=20
> (See 8d8e1438ae5a2e50005b500dacd0a26be540fe69 and
> b6bfe9ea6a1b19159455b34f1af4ac00ef9b94ab)
>=20
> And some commits with large body are around:
>=20
> + 7b45ead9ec40a5ea1ef8332d55c2bb4beff85eb5 from Jul 18 2023
> + 1e6ddceb8318d413745ca1c9d91fde01b1e0364b from Feb 19 2023
> + 5897d873d0c902f08d13c38500eff11098f2a634 from Aug 10 2022
>=20
> And I have not investigated more about their commit object size. Just
> counting the number of characters per commit message. The one you
> provided is about 3030, if I am correct. Here, let filter with the
> criteria of 4500, why not. :-)
>=20
> --8<---------------cut here---------------start------------->8---
> $ for ci in $(git log --format=3D%H --after=3D2022-05-13); do \
> echo "$(git show -s $ci | wc -c) $ci" \
> | awk '$1>4500{print $2 " " $1}' \
> ;done=20
> 7b45ead9ec40a5ea1ef8332d55c2bb4beff85eb5 4997
> 1e6ddceb8318d413745ca1c9d91fde01b1e0364b 16120
> 575a03ab3997edee08d20867228e886043d5240f 5511
> 5897d873d0c902f08d13c38500eff11098f2a634 6258
> --8<---------------cut here---------------end--------------->8---
>=20
> Well, it is probably not a regression. Or I am missing some details. :-)
Thank you for raising this up and making me look into it closer. The issue
(commits not being eq? to themselves) does happen for those listed above,
however commit-relation still works fine. I am unsure why, I spent most of
today on it and did not manage to find clear rules.
However the fact remains that when one is on
d51135e8477118dc63a7e5462355cd27e884f4fb, guix pull to
4dbd25fa0e09b40ba2ab01d1e64fa36db652b501 does fail. I pushed those commits=
into
https://git.sr.ht/~graywolf/guix-guile-git-repro as branch xxx in case anyo=
ne is
curious and wants to investigate.
>=20
> I am probably overlooking something, from my understanding, the issue
> arises for some corner cases when the bound of the closure does not fit
> =E2=80=99eq?=E2=80=99. For these cases, instead of relying on =E2=80=99s=
etq=E2=80=99 using =E2=80=99eq?=E2=80=99, we
> could rely on =E2=80=99set=E2=80=99 using =E2=80=99equal?=E2=80=99. No?
I do not believe so, the mismatch happens even for equal?. I do not know e=
nough
about scheme to know whether guile-git could override equal? for the commit
record type, but it does not seem to do so.
scheme@(guile-user)> (use-modules (git) (guix git))
scheme@(guile-user)> (define %repo (repository-open "/home/wolf/src/gui=
x"))
scheme@(guile-user)> (define %hash "1e6ddceb8318d413745ca1c9d91fde01b1e=
0364b")
scheme@(guile-user)> (equal? (commit-lookup %repo (string->oid %hash)) =
(commit-lookup %repo (string->oid %hash)))
$1 =3D #f
>=20
> On Fri, 29 Sep 2023 at 18:52, wolf <wolf@HIDDEN> wrote:
>=20
> > ,----
> > | scheme@(guile-user)> (use-modules (git) (guix git))
> > | scheme@(guile-user)> (define %repo (repository-open "/tmp/my-fork"))
> > | scheme@(guile-user)> (define %hash "d51135e8477118dc63a7e5462355cd2=
7e884f4fb")
> > | scheme@(guile-user)> (commit-relation
> > | (commit-lookup %repo (string->oid %hash))
> > | (commit-lookup %repo (string->oid %hash)))
> > | $5 =3D unrelated
> > `----
>=20
> [...]
>=20
> > ,----
> > | $ git merge-base --is-ancestor 9b985229bcd 71f544c102a; echo $?
> > | 0
> > `----
>=20
> [...]
>=20
> > 2 Possible solutions
> > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>=20
> Naive question. Why not rely on =E2=80=9Cgit merge-base --is-ancestor=E2=
=80=9D for
> implementing =E2=80=9Ccommit-relation=E2=80=9D?
>=20
> Since f651a359691cbe4750f1fe8d14dd964f7971f91 from Sep 26 2023:
>=20
> build: Add dependency on Git.
>=20
> * configure.ac: Check for =E2=80=98git=E2=80=99 and substitute =E2=80=
=98GIT=E2=80=99.
> * guix/config.scm.in (%git): New variable.
> * guix/self.scm (compiled-guix): Define =E2=80=98git=E2=80=99 and pas=
s it to
> =E2=80=98make-config.scm=E2=80=99.
> (make-config.scm): Add #:git; emit a =E2=80=98%git=E2=80=99 variable.
> * doc/guix.texi (Requirements): Add it.
>=20
> we can assume Git is available by the code that run =E2=80=9Ccommit-relat=
ion=E2=80=9D,
> no?
>=20
> The implementation relying on =E2=80=9Cgit merge-base --is-ancestor=E2=80=
=9D does not
> have the problem, right?
Well, that is true. I forgot to mention this option, because there did not=
seem
to be a consensus regarding replacing more parts of guile-git with git prop=
er.
But this would likely be the best solution if that approach is acceptable.
>=20
> And from [1], it is 35x faster. Win-win, no? Because the fix for =E2=80=
=99eq?=E2=80=99
> will introduce performance cost and =E2=80=99commit-relation=E2=80=99 wil=
l be even
> slower, no?
For what it is worth, the implementation using <commit-set> (I needed it fo=
r my
fork to be able to pull) is not noticeably slower. The slow down is likely
measurable, but since I did not even notice it I did not bother measuring i=
t.
Not that I am arguing against using git.
>=20
> Well, I do not know. My words are probably irrelevant.
>=20
> Cheers,
> simon
>=20
>=20
> 1: comparing commit-relation using Scheme+libgit2 vs shellout plumbing Git
> Simon Tournier <zimon.toutoune@HIDDEN>
> Tue, 12 Sep 2023 00:48:30 +0200
> id:865y4gz5q9.fsf@HIDDEN
> https://lists.gnu.org/archive/html/guix-devel/2023-09
> https://yhetil.org/guix/865y4gz5q9.fsf@HIDDEN
--=20
There are only two hard things in Computer Science:
cache invalidation, naming things and off-by-one errors.
--+UQ01KY/FuPcIZvY
Content-Type: application/pgp-signature; name="signature.asc"
-----BEGIN PGP SIGNATURE-----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=02wv
-----END PGP SIGNATURE-----
--+UQ01KY/FuPcIZvY--
bug-guix@HIDDEN:bug#66268; Package guix.
Full text available.
Received: (at 66268) by debbugs.gnu.org; 2 Oct 2023 09:21:23 +0000
From debbugs-submit-bounces <at> debbugs.gnu.org Mon Oct 02 05:21:22 2023
Received: from localhost ([127.0.0.1]:36039 helo=debbugs.gnu.org)
by debbugs.gnu.org with esmtp (Exim 4.84_2)
(envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>)
id 1qnF79-0007Qz-12
for submit <at> debbugs.gnu.org; Mon, 02 Oct 2023 05:21:22 -0400
Received: from mail-wr1-x436.google.com ([2a00:1450:4864:20::436]:40407)
by debbugs.gnu.org with esmtp (Exim 4.84_2)
(envelope-from <zimon.toutoune@HIDDEN>) id 1qnF71-0007Q5-IX
for 66268 <at> debbugs.gnu.org; Mon, 02 Oct 2023 05:21:15 -0400
Received: by mail-wr1-x436.google.com with SMTP id
ffacd0b85a97d-32163c3ece5so1990525f8f.1
for <66268 <at> debbugs.gnu.org>; Mon, 02 Oct 2023 02:20:54 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=gmail.com; s=20230601; t=1696238449; x=1696843249; darn=debbugs.gnu.org;
h=content-transfer-encoding:mime-version:message-id:date:references
:in-reply-to:subject:to:from:from:to:cc:subject:date:message-id
:reply-to; bh=x9FCYtfbJ2+U16ZKW8LQb0DAS1/6j9f2E0l9cczmbs0=;
b=gewYlxeArhBTVbJZlNTtT2DprV8LBPx+uGBGcezjcioeHGhnf+aiBptVWumygaylSS
Qf35wNwW8WPghb59GgrsSz05f9grxltiT0RkQwR2qf9DAV+ubdjdJczj8YUaHxIEi4wD
a47a/9Q3ysJGJhfQ/Oxv6J9ozopkBSpclFGVWlnm9BzvE8IEZuhIrOKoyUMCT3S8ge1Q
K7trknlvxylPUC9lIpcvhTtCDFL3Lo6ukidZDZsdGZweKjsaTY3ERkylANi32IpCiWAB
OhyYsVgfLs/Z+NcFX8vZDUCRS0YLVrCafPKqMyWzJg7UHvOb+qIvh6gZRF9MvHqTCTrw
Nb6w==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20230601; t=1696238449; x=1696843249;
h=content-transfer-encoding:mime-version:message-id:date:references
:in-reply-to:subject:to:from:x-gm-message-state:from:to:cc:subject
:date:message-id:reply-to;
bh=x9FCYtfbJ2+U16ZKW8LQb0DAS1/6j9f2E0l9cczmbs0=;
b=j2m1rkuOJYhyk/pNtttE49xkw/FVmuMXOEK3avS9lXc4XjrI8d+aShnhBs/qFn/DQC
+QPk5mMvM9EC5PvN2sn4RwE1LNbxSmIC7WRLM0ZCLqwkYjDJc/PvVS0Mgka4GSQvmRJF
GsYilNFokhu87vaZtdXBJbcmf13ag4X5jnAVrnZttAEkggU7wq8gacETVxug+aWAAMk5
ouFPrWkugDXomveruvqRivP/ZXP7bu2LfbxG2CWZjkS8VlMQ921RUUuGO/07nQyS25gJ
iuo745HXp7gvBpyJfVgfD8TJJg3CLVURuQQ+oCzQ5fdzPn4MlvpNFIkOuylxen1TCNyr
WYeQ==
X-Gm-Message-State: AOJu0Yzlyie6GPn7Rx6aSYpvE/RFWW5qWTbkp3qlx6sj/A4PoJ9Y6q25
jDvsc6IrITcn9HfoZ4T1Fu1GIc84cls=
X-Google-Smtp-Source: AGHT+IFgStVQGZgQUZ5jgCIwBmQM98xj5vb+9fYWjOqLUaGwlBvUwb/Y9u41Dduu513HSivOP2hVig==
X-Received: by 2002:a5d:6909:0:b0:322:5251:d78b with SMTP id
t9-20020a5d6909000000b003225251d78bmr8945769wru.6.1696238447809;
Mon, 02 Oct 2023 02:20:47 -0700 (PDT)
Received: from lili ([2a01:e0a:59b:9120:65d2:2476:f637:db1e])
by smtp.gmail.com with ESMTPSA id
p5-20020a5d4585000000b0031ad5470f89sm27581510wrq.18.2023.10.02.02.20.47
(version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);
Mon, 02 Oct 2023 02:20:47 -0700 (PDT)
From: Simon Tournier <zimon.toutoune@HIDDEN>
To: wolf <wolf@HIDDEN>, 66268 <at> debbugs.gnu.org
Subject: Re: bug#66268: Guix makes invalid assumptions regarding guile-git
guarantees leading to guix pull failing
In-Reply-To: <ZRcA23RUYvBuE1JX@ws>
References: <ZRcA23RUYvBuE1JX@ws>
Date: Sat, 30 Sep 2023 17:48:55 +0200
Message-ID: <86fs2vek60.fsf@HIDDEN>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
X-Spam-Score: 0.5 (/)
X-Debbugs-Envelope-To: 66268
X-BeenThere: debbugs-submit <at> debbugs.gnu.org
X-Mailman-Version: 2.1.18
Precedence: list
List-Id: <debbugs-submit.debbugs.gnu.org>
List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>,
<mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe>
List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/>
List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org>
List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help>
List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>,
<mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe>
Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org
Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org>
X-Spam-Score: -0.5 (/)
Hi,
Hum, the updates seem:
+ libgit2 on Feb 17 2023,
+ guile-git on May 15 2022.
(See 8d8e1438ae5a2e50005b500dacd0a26be540fe69 and
b6bfe9ea6a1b19159455b34f1af4ac00ef9b94ab)
And some commits with large body are around:
+ 7b45ead9ec40a5ea1ef8332d55c2bb4beff85eb5 from Jul 18 2023
+ 1e6ddceb8318d413745ca1c9d91fde01b1e0364b from Feb 19 2023
+ 5897d873d0c902f08d13c38500eff11098f2a634 from Aug 10 2022
And I have not investigated more about their commit object size. Just
counting the number of characters per commit message. The one you
provided is about 3030, if I am correct. Here, let filter with the
criteria of 4500, why not. :-)
--8<---------------cut here---------------start------------->8---
$ for ci in $(git log --format=3D%H --after=3D2022-05-13); do \
echo "$(git show -s $ci | wc -c) $ci" \
| awk '$1>4500{print $2 " " $1}' \
;done=20
7b45ead9ec40a5ea1ef8332d55c2bb4beff85eb5 4997
1e6ddceb8318d413745ca1c9d91fde01b1e0364b 16120
575a03ab3997edee08d20867228e886043d5240f 5511
5897d873d0c902f08d13c38500eff11098f2a634 6258
--8<---------------cut here---------------end--------------->8---
Well, it is probably not a regression. Or I am missing some details. :-)
I am probably overlooking something, from my understanding, the issue
arises for some corner cases when the bound of the closure does not fit
=E2=80=99eq?=E2=80=99. For these cases, instead of relying on =E2=80=99set=
q=E2=80=99 using =E2=80=99eq?=E2=80=99, we
could rely on =E2=80=99set=E2=80=99 using =E2=80=99equal?=E2=80=99. No?
On Fri, 29 Sep 2023 at 18:52, wolf <wolf@HIDDEN> wrote:
> ,----
> | scheme@(guile-user)> (use-modules (git) (guix git))
> | scheme@(guile-user)> (define %repo (repository-open "/tmp/my-fork"))
> | scheme@(guile-user)> (define %hash "d51135e8477118dc63a7e5462355cd27e=
884f4fb")
> | scheme@(guile-user)> (commit-relation
> | (commit-lookup %repo (string->oid %hash))
> | (commit-lookup %repo (string->oid %hash)))
> | $5 =3D unrelated
> `----
[...]
> ,----
> | $ git merge-base --is-ancestor 9b985229bcd 71f544c102a; echo $?
> | 0
> `----
[...]
> 2 Possible solutions
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
Naive question. Why not rely on =E2=80=9Cgit merge-base --is-ancestor=E2=
=80=9D for
implementing =E2=80=9Ccommit-relation=E2=80=9D?
Since f651a359691cbe4750f1fe8d14dd964f7971f91 from Sep 26 2023:
build: Add dependency on Git.
* configure.ac: Check for =E2=80=98git=E2=80=99 and substitute =E2=80=
=98GIT=E2=80=99.
* guix/config.scm.in (%git): New variable.
* guix/self.scm (compiled-guix): Define =E2=80=98git=E2=80=99 and pass =
it to
=E2=80=98make-config.scm=E2=80=99.
(make-config.scm): Add #:git; emit a =E2=80=98%git=E2=80=99 variable.
* doc/guix.texi (Requirements): Add it.
we can assume Git is available by the code that run =E2=80=9Ccommit-relatio=
n=E2=80=9D,
no?
The implementation relying on =E2=80=9Cgit merge-base --is-ancestor=E2=80=
=9D does not
have the problem, right?
And from [1], it is 35x faster. Win-win, no? Because the fix for =E2=80=
=99eq?=E2=80=99
will introduce performance cost and =E2=80=99commit-relation=E2=80=99 will =
be even
slower, no?
Well, I do not know. My words are probably irrelevant.
Cheers,
simon
1: comparing commit-relation using Scheme+libgit2 vs shellout plumbing Git
Simon Tournier <zimon.toutoune@HIDDEN>
Tue, 12 Sep 2023 00:48:30 +0200
id:865y4gz5q9.fsf@HIDDEN
https://lists.gnu.org/archive/html/guix-devel/2023-09
https://yhetil.org/guix/865y4gz5q9.fsf@HIDDEN
bug-guix@HIDDEN:bug#66268; Package guix.
Full text available.Received: (at submit) by debbugs.gnu.org; 29 Sep 2023 16:53:25 +0000 From debbugs-submit-bounces <at> debbugs.gnu.org Fri Sep 29 12:53:25 2023 Received: from localhost ([127.0.0.1]:57069 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>) id 1qmGk0-0007HV-UW for submit <at> debbugs.gnu.org; Fri, 29 Sep 2023 12:53:25 -0400 Received: from lists.gnu.org ([2001:470:142::17]:53076) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <ws@HIDDEN>) id 1qmGjx-0007H3-I2 for submit <at> debbugs.gnu.org; Fri, 29 Sep 2023 12:53:22 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from <ws@HIDDEN>) id 1qmGjW-0004Hc-VR for bug-guix@HIDDEN; Fri, 29 Sep 2023 12:52:57 -0400 Received: from wolfsden.cz ([37.205.8.62]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from <ws@HIDDEN>) id 1qmGjS-0005zr-69 for bug-guix@HIDDEN; Fri, 29 Sep 2023 12:52:54 -0400 Received: by wolfsden.cz (Postfix, from userid 104) id 9E2CF25FF78; Fri, 29 Sep 2023 16:52:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=wolfsden.cz; s=mail; t=1696006364; bh=oj5b7mUnaSSEcmecccWHc8TpJO3BG/H+9sF0J8SdrXY=; h=Date:From:To:Subject; b=KQOM5AIw0B1RoyIfKN0EEb8gW4xRu06B2q95muApiXVPo8zSS76/O+WeQb1JDyXbQ 6w4GBo6vr1hOrJIaWaLv9KYW+lhdQ9pxLH9chE1T9mpftHH4I8qlYhIclfj0kDfaQ3 eTgjpKlUose7Bzij2TGwLRi4/SR0hOJp9gsKhCpoHbrZJ350H1ZgqosmY7hUEJqIHM rABntmuNAeU/tHvK3CGEdYkwsNUe8TyEAWnzw3TR52Qqx6d8BffnpAt1ctiUsLDvlC /kK2udLWVFJjzhwwEdqhW4EsTNi2QtIJo4L8tq7RiY0X3kSWCEUbkWuHUFpq8rAl1U BUnsjiNP6UxsMpouO5+5h3Yt92E6tjKSHvi59PwvKzcNWScJ+eezQOM9XUEHUH+Xfg 8SlRSJjqxayImrWyv+FoDyNXrB2uqf8tyYGH0hc35hK/0WxXRGAJvapptiympiz7FZ dhqyFrfD8l5i9OrAsvwpM3BHM/1kM/czFU2GYVm8I0Hng5xy/U9TRrxSB4/OErUYMl 3vOcoNedM9f6wnBchoCav6vp45kZoS4s+zu7E03p0+bXo+hdwxxVhyPLkSp+k5T4F6 xQpe34yqQsYxS7HlBdlz7JuCWDzVc1e/Fw9WX7Ez4CVxkoSisrdaCS+pYoE+GdJ7kh jNripxij7OJHlYfaJyx88Y94= X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on wolfsden X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=ALL_TRUSTED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.6 Received: from localhost (unknown [81.17.16.87]) by wolfsden.cz (Postfix) with ESMTPSA id B2B0625FF77 for <bug-guix@HIDDEN>; Fri, 29 Sep 2023 16:52:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=wolfsden.cz; s=mail; t=1696006363; bh=oj5b7mUnaSSEcmecccWHc8TpJO3BG/H+9sF0J8SdrXY=; h=Date:From:To:Subject; b=AgiAvD/dLnNhjpqRI6h6XCY2F096U5+17Kc4V9havYCnBs9ZkLroRIS8MUx3cheFV DDnCEpxmuRrlA4Rvc66tKWMVqfS0qixqzPkw/R28bSw6b3P5Drc/6Dumra6lLOjK44 CUfaizJiGLryr6xBuuvtmyqeDPzxl9mPwozUEas7ufuC10pv5pfSkUA4ffHXN09i9x 8givr7fVLRC5lNs1M2W9gwr3h2jZWVY72/PtkFvzlbKo7ds7FB8a6gM69asL+V3pP/ rzc2IE4/XH2ztoEPvfVBX4loi1Y+4fp2qLi+1XoxNQs6pM7efldS8kGETGoOB4ovEL 2PLc43FYLU+eZNxIFZAeOqkhHaFnZQHN2eDPJHO1fFyLuzVl2rz+ttutEwOp/cvIIr 7Gp9DZACEPaw8CKIpttWUxfxq/voDs9O2B2Y1nyOwoGrflvfU/FJ750A8rAEBLrpRW aVhVLJPqp++y7XVLQsT45+2L7o/n4X+GGpP68aSKZ0/0RREqzd8jwOIE0XAbzgVmXJ ZPpGQ8EaXDmQsGV9djHYGYfNTGzj1DIe3lTs/QyYx1gS/LuceRlZm4HL1RQGB4PMdU 8zElGYm7teovOIctb5C9RYH2NCToOoixXvy+aK5LiJjmo+XVFLwdqOZDqiQZ+nonQQ FSQazIoPKP38UHzf7ddvdb8g= Received: from localhost (localhost [local]) by localhost (OpenSMTPD) with ESMTPA id 8b14761c for <bug-guix@HIDDEN>; Fri, 29 Sep 2023 16:52:43 +0000 (UTC) Date: Fri, 29 Sep 2023 18:52:43 +0200 From: wolf <wolf@HIDDEN> To: bug-guix@HIDDEN Subject: Guix makes invalid assumptions regarding guile-git guarantees leading to guix pull failing Message-ID: <ZRcA23RUYvBuE1JX@ws> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="pesXC/INFpw/3QMw" Content-Disposition: inline Received-SPF: none client-ip=37.205.8.62; envelope-from=ws@HIDDEN; helo=wolfsden.cz X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_HELO_PASS=-0.001, SPF_NONE=0.001, UNPARSEABLE_RELAY=0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-Spam-Score: 0.2 (/) X-Debbugs-Envelope-To: submit X-BeenThere: debbugs-submit <at> debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: <debbugs-submit.debbugs.gnu.org> List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>, <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe> List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/> List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org> List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help> List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>, <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe> Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org> X-Spam-Score: -0.8 (/) --pesXC/INFpw/3QMw Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Table of Contents _________________ 1. Guix makes an invalid assumption regarding guile-git's guarantees =2E. 1. Root cause analysis =2E.... 1. Object size =2E.... 2. Cache space =2E. 2. Reproduction to verify the analysis 2. Possible solutions =2E. 1. Do not use `eq?' =2E. 2. Increase the cache size / limits =2E. 3. Ensure the id stability in guile-git 3. Questions =2E. 1. Is this a regression? 4. Attachments =2E. 1. d51135e8477118dc63a7e5462355cd27e884f4fb =2E. 2. test.scm 1 Guix makes an invalid assumption regarding guile-git's guarantees =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D There is an assumption made by Guix regarding guile-git, which is not true. The problem is demonstrated using my fork, since that is where I encountered it first, but official Guix will hit the same problem sooner or later. I will also provide an independent repository for the verification. Guix made a design decision to compare commit objects using eq?, based on the assumption that guile-git will return the same object for the same commit. However that assumption is wrong and can lead to fun issues like: ,---- | scheme@(guile-user)> (use-modules (git) (guix git)) | scheme@(guile-user)> (define %repo (repository-open "/tmp/my-fork")) | scheme@(guile-user)> (define %hash "d51135e8477118dc63a7e5462355cd27e88= 4f4fb") | scheme@(guile-user)> (commit-relation | (commit-lookup %repo (string->oid %hash)) | (commit-lookup %repo (string->oid %hash))) | $5 =3D unrelated `---- This does break (at least) `guix pull': ,---- | Updating channel 'guix' from Git repository at 'https://git.sr.ht/~gray= wolf/guix'... | guix pull: error: aborting update of channel 'guix' to commit 4dbd25fa0= e09b40ba2ab01d1e64fa36db652b501, which is not a descendant of d51135e847711= 8dc63a7e5462355cd27e884f4fb | hint: This could indicate that the channel has been tampered with and i= s trying to force a roll-back, preventing you from getting the latest updat= es. If you think this is not the case, | explicitly allow non-forward updates. `---- The commit actually is a descendant, but it is not found in the `commit-closure' due to the `eq?' comparison being used. The verification of the relation between the commits: ,---- | $ git log --first-parent --oneline -4 | 4dbd25fa0e (HEAD -> master, origin/master) etc/fork-guix: Use absolute = path for the patch file. | 601029b97a Merge updates from the Guix proper | afa5eabc93 git-authenticate: Fix tracking of trusted parents. | d51135e847 Merge updates from the Guix proper `---- 1.1 Root cause analysis ~~~~~~~~~~~~~~~~~~~~~~~ Guile-git is a wrapper around libgit2, and libgit2 (as far as I can tell) makes no guarantees about returning the same commit object every time lookup is performed for the same hash. It just does it, sometimes, due to the internal use of a cache. There are two rules in place. 1.1.1 Object size ----------------- Object has to be smaller than configured size limit for the object type. For commits, that is 4096B. It can be increased (`git_libgit2_opts' called with `GIT_OPT_SET_CACHE_OBJECT_LIMIT'), but guile-git does not offer any binding for that functionality. In the case illustrated above, the commit object for 4.1 has size of 4139B, and is therefore never cached. That means that a new object is returned every time, and therefore they are never considered equal by Guix. As you can see, the commit message, while long, is sensible and useful, so it is fairly easy to hit the limit. 1.1.2 Cache space ----------------- Cache is limited to 268435456B, and it is pruned if the need to get more space arises. That is especially problematic because it could lead to hard to debug failures based on the access pattern to the repository. Typical signed commit seems to be larger than 1kB. Based on the cache size, rough calculation suggests that Guix (which requires the commits to be signed) can only store somewhere around 252052 commits before running into possible issues. Currently there are 64416 commits since the channel introduction, so we are already getting close and it *will* be a problem in the future, even if we keep the commits smallish. 1.2 Reproduction to verify the analysis ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To verify that the analysis above is correct, I created a test repository to run tests against. `head' refers to a commit at the HEAD, it is a small one (210B libgit2's entry size). `large' refers to a commit with a large (4kB) commit message, it is the parent of `head'. `root' refers to the root commit. All other commits are of 210B entry size. The repository is located here[0]. When the 4.2 is executed, it seems to support the conclusions reached in previous section. The output when executed on my machine is: ,---- | Checking (eq? (%commit X) (find-c (%hash X))) for X: |=20 | ;;; (large #f) |=20 | ;;; (head #t) |=20 | ;;; (root #t) | Collecting all commits... | Checking if they match themselves... | # of mismatches 300530 of 1578267 commits | Relation between 'head and 'large: unrelated `---- We can see that both `head' and `root' do match themselves, since they are small and fit into the cache. However `large' does not fit into the cache, and therefore we get new, distinct, object from each `commit-lookup' call. That seems to confirm the hypothesis regarding the limit on object size that fits into the cache. After that we record all commits into a vhash, overwhelming the cache and forcing evictions. After that we do a second sweep to check how many of the commit will match itself. We can see that about 20% of commits do not match, confirming the hypothesis regarding the cache capacity. And finally we see that `head' and `large' are unrelated, despite that not being the case, after all, `head' is the parent of `large'. Git tooling does confirm that: ,---- | $ git merge-base --is-ancestor 9b985229bcd 71f544c102a; echo $? | 0 `---- 0: <https://git.sr.ht/~graywolf/guix-guile-git-repro> 2 Possible solutions =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 2.1 Do not use `eq?' ~~~~~~~~~~~~~~~~~~~~ The correct solution is to stop using `eq?' to compare the commits (and other objects from guile-git, if that is being done). That will come at some performance cost, but the benefit of being actually correct does out-weight that. My partial solution is based on new record type, `<commit-set>', to use instead of (guix sets). ,---- | (define-record-type <commit-set> | (%make-commit-set vhash) | commit-set? | (vhash commit-set-vhash)) |=20 | (define (make-commit-set) | (%make-commit-set vlist-null)) |=20 | (define (commit-set-contains? commit commit-set) | (->bool (vhash-assoc (oid->string (commit-id commit)) | (commit-set-vhash commit-set)))) |=20 | (define (commit-set-insert commit commit-set) | (%make-commit-set (vhash-cons (oid->string (commit-id commit)) | #t | (commit-set-vhash commit-set)))) `---- It is not complete, for example I do not check that the commits do come from the same repository. However I believe similar approach is the preferred solution. 2.2 Increase the cache size / limits ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ While the size limit for objects to be cache-able is configurable, the maximum size of the cache is hard coded. However patching libgit2 is always an option. But this does not really solve the issue, it just pushes it down the line. Removing the size limits is also an option, but would lead to unbound memory usage. 2.3 Ensure the id stability in guile-git ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Technically it should be possible to improve guile-git to ensure the object stability without patching the libgit2, but it would basically involve a second cache, without size limits. It could probably utilize weak hash tables to make the memory usage reasonable. However it would be tricky to make sure everything is correctly wrapped. 3 Questions =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 3.1 Is this a regression? ~~~~~~~~~~~~~~~~~~~~~~~~~ Since this was the approach chosen by Guix, did guile-git or libgit2 used to guarantee this? Should this be reported as a regression? 4 Attachments =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 4.1 d51135e8477118dc63a7e5462355cd27e884f4fb ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ,---- | commit d51135e8477118dc63a7e5462355cd27e884f4fb | Merge: 75daa689f1 0500af5556 | Author: Tomas Volf <wolf@HIDDEN> | Date: Wed Sep 27 21:03:40 2023 +0200 |=20 | Merge updates from the Guix proper | =20 | * upstream/master: | Revert "build: Add missing guix-gc.timer file to binary tarball." | gnu: tio: Update to 2.7. | gnu: bcachefs-tools: Restore mount.bcachefs shell script version. | gnu: bcachefs-tools: Remove obsolete phase. | gnu: bcachefs-tools: Update to 1.2-0.1e35840. | Revert "gnu: bcachefs-tools: Restyle format." | gnu: sssd: Update to 2.9.2. | gnu: wvkbd: Update to 0.14.1. | gnu: yt-dlp: Update to 2023.09.24. | gnu: lhasa: Update to 0.4.0. | gnu: vcmi: Update to 1.3.2. | gnu: cmark: Update to 0.30.3. | gnu: python-tslearn: Update to 0.6.2. | gnu: python-astropy: Update to 5.3.3. | gnu: python-stdatamodels: Update to 1.8.0. | gnu: python-roman-datamodels: Remove all test constraints. | gnu: python-roman-datamodels: Update to 0.17.1. | gnu: python-rad: Update to 0.17.1. | gnu: python-pyvo: Update to 1.4.2. | gnu: python-photutils: Update to 1.9.0. | gnu: python-jwst: Update to 1.11.4. | gnu: python-fitsio: Update to 1.2.0. | gnu: python-crds: Update to 11.17.4. | gnu: python-bayesicfitting: Update to 3.2.0. | gnu: python-sunpy: Enable more tests. | gnu: python-cdflib: Fix version detection. | gnu: python-cdflib: Update to 1.1.0. | gnu: python-astropy-healpix: Update to 1.0.0. | gnu: splash: Update to 3.8.4. | gnu: libxisf: Extend description. | gnu: libxisf: Update to 0.2.9. | gnu: python-coloful: Update to 0.5.5. | gnu: python-pyotp: Update to 2.9.0. | gnu: gajim: Clean up formatting. | gnu: python-nbxmpp: Clean up formatting. | gnu: gajim-openpgp: Update to 1.5.0. | gnu: gajim-omemo: Update to 2.9.0. | gnu: gajim: Update to 1.7.3. | gnu: python-nbxmpp: Update to 4.2.2. | gnu: transmission: Fix loading icons in pure environments. | gnu: alex4: Remove non-free package. | doc: Update bug-reference configuration snippet. | tests: Assume =E2=80=98git=E2=80=99 is always available. | git-download: Use =E2=80=9Cbuiltin:git-download=E2=80=9D when ava= ilable. | perform-download: Use the =E2=80=98git=E2=80=99 command captured = at configure time. | build: Add dependency on Git. | daemon: Add =E2=80=9Cgit-download=E2=80=9D built-in builder. | perform-download: Remove unused one-argument clause. | git-download: Honor the =E2=80=98GUIX_DOWNLOAD_FALLBACK_TEST=E2= =80=99 environment variable. | git-download: Move fallback code to (guix build git). | tests: Adjust =E2=80=98guix graph --path=E2=80=99 test to latest = Emacs changes. | gnu: imgui: Update to 1.89.9. | gnu: Add tracy. | gnu: Add tracy-wayland. | gnu: glfw: Patch dlopen calls. | gnu: imgui: Enable freetype support. | gnu: capstone: Update to 5.0.1. | gnu: gtypist: Install the gtypist-mode Emacs major mode. | multiqc: Don't propagate inputs. | gnu: transmission: Restore HTML files in the default output. | gnu: aalib: Really build the shared library on powerpc64le-linux. | gnu: edk2-tools: Update to 202308. | doc: Add new 'Circular Module Dependencies' section. | gnu: embedded: Turn packages using top-level variables into proce= dures. | gnu: avr: Delay all cross compilation packages. | gnu: Add satdump. | gnu: nng: Update to 1.5.2. | gnu: sdrangel: Update to 7.16.0. `---- 4.2 test.scm ~~~~~~~~~~~~ ,---- | (use-modules (ice-9 vlist) | (git) | (guix git)) |=20 | ;;; Tweak the path as necessary. | (define %repo (repository-open "/home/wolf/tmp/guix-guile-git-repro")) |=20 | ;;; All hashes that are of interest to us. | (define %hashes '((large . "9b985229bcd447261b147c6bf70a86c2a345f234") | (head . "71f544c102a658ed5f2f2258862f2d59cbe70b8b") | (root . "db3f74122f4c384897ba7fddac73b893d19c1c67"))) | (define (%hash for) | "Return a sha1 hash for a specified key." | (assoc-ref %hashes for)) |=20 | (define %Xs | (map car %hashes)) |=20 | (define (find-c hash) | "Return a commit based on the string sha1 hash." | (commit-lookup %repo (string->oid hash))) |=20 | ;;; Memoize the commits so that we can compare against them later. | (define %commits (map (=CE=BB (k) `(,k . ,(find-c (%hash k)))) | %Xs)) | (define (%commit for) | "Return a memoized commit for a specified key." | (assoc-ref %commits for)) |=20 | (display "Checking (eq? (%commit X) (find-c (%hash X))) for X:\n") | (for-each (=CE=BB (x) | (pk x (eq? (%commit x) (find-c (%hash x))))) | %Xs) |=20 | (display "Collecting all commits...\n") | (define all-commits | (let loop ((commits vlist-null) | (hash (%hash 'head))) | (let* ((c (find-c hash)) | (parents (commit-parents c)) | (commits (vhash-cons (oid->string (commit-id c)) | c | commits))) | (if (null? parents) | commits | (loop commits | (oid->string (commit-id (car parents)))))))) | (display "Checking if they match themselves...\n") | (format #t "# of mismatches ~a of ~a commits\n" | (vlist-fold (=CE=BB (x total) | (let ((hash (car x)) | (commit (cdr x))) | (if (eq? commit (find-c hash)) | total | (+ total 1)))) | 0 | all-commits) | (vlist-length all-commits)) |=20 | (format #t "Relation between 'head and 'large: ~a\n" | (commit-relation (%commit 'head) | (%commit 'large))) `---- Have a nice day, W. --=20 There are only two hard things in Computer Science: cache invalidation, naming things and off-by-one errors. --pesXC/INFpw/3QMw Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEt4NJs4wUfTYpiGikL7/ufbZ/wakFAmUXANUACgkQL7/ufbZ/ wakODA/8DxkKlgO32+U9sJxD0ZS8QN7Hua1SzsUmVChlPasuFqHgqx0Exu9y8qSv I7N72W0zam6LEjWtGhzfF8kTamtrNALObqPi6Xw21VrXm4iO2LFQy9tZaGAxQvtb +I8CCVtAxS/Gk8ehCYGXpGpeafE0/TBzB/b+0Mjqx+KdAq7amWTzLGo8/5O1Qe8l Zrr+VW2KdYCDRi6qMR5DsxCQin38m8yuYiD/mX7vjTF6w/XHf73U9QqzTNwYwYLi vgEscW+5VbseEE3ESyyei9S0H2cORfRT2UIFZGwsg6IZE1nHCD+lQjfPdGl8pIo8 3iFWgffkOYdp6zqo1VLPNcEGIDwvN5JdPRE3O+skqzCUhfoT9a3wymDgd/92HDKp YvxNiGLQfXmXIq3UsCbBIAvSy6wec+rn8twxRDFf8fNlB1Ma8UPUXwV0h3TSFet5 xWlMeTyki/uWcLDSBSaVt5SyRvKw3DZ9XO+G6L91G5KqdWvjn/Ll03OuHezM8K7I SIhcZylwdEhBCRdZr6JVN/uu005nkhKQ1omgi8hjsZaHGZFVg9o9+r22n5cFPOol 6ocs4DDXf81fMuhY48FB4+/9Ha62xsO/m/tEhFsNEqrCIPe9ciAPjoa5ElPsYaiI iJEwqduWUGCQ9TXWS1ZyKhIZkG9iO2DU7e+4GGP9BwSjzEQp0iU= =yCeP -----END PGP SIGNATURE----- --pesXC/INFpw/3QMw--
wolf <wolf@HIDDEN>:bug-guix@HIDDEN.
Full text available.bug-guix@HIDDEN:bug#66268; Package guix.
Full text available.
GNU bug tracking system
Copyright (C) 1999 Darren O. Benham,
1997 nCipher Corporation Ltd,
1994-97 Ian Jackson.