Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 31 Mar 2022 15:23:01 -0300
From:   Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
To:     Andres Freund <andres@anarazel.de>,
        Matthieu Baerts <matthieu.baerts@tessares.net>
CC:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        John Garry <john.garry@huawei.com>, mptcp@lists.linux.dev,
        Arnaldo Carvalho de Melo <acme@redhat.com>,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH perf] perf tools: .git/ORIG_HEAD might not exist
User-Agent: K-9 Mail for Android
In-Reply-To: <20220331173344.xvhp4yi67fv6p6t5@alap3.anarazel.de>
References: <20220329093120.4173283-1-matthieu.baerts@tessares.net> <20220331173344.xvhp4yi67fv6p6t5@alap3.anarazel.de>
Message-ID: <5B37F7F6-CDFD-49B9-9BF6-CEA726E5F0CF@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain;
 charset=utf-8
Content-Transfer-Encoding: quoted-printable
Precedence: bulk


On March 31, 2022 2:33:44 PM GMT-03:00, Andres Freund <andres@anarazel=2Ed=
e> wrote:
>Hi,
>
>On 2022-03-29 11:31:20 +0200, Matthieu Baerts wrote:
>> It seems it cannot be assumed =2Egit/ORIG_HEAD exists if =2Egit/HEAD is
>> there=2E
>>=20
>> Indeed, recently our public CI reported[1] the following error when
>> compiling Perf tool:
>>=20
>>   $ cd tools/perf
>>   $ make -j4 -l4 O=3D/tmp/(=2E=2E=2E)/perf DESTDIR=3D/usr install
>>   (=2E=2E=2E)
>>   make[2]: *** No rule to make target '=2E=2E/=2E=2E/=2Egit/ORIG_HEAD',=
 needed by '/tmp/(=2E=2E=2E)/perf/PERF-VERSION-FILE'=2E
>>=20
>> This is because apparently[2] Cirrus Ci uses a Git client implemented
>> purely in Go[3] to perform a clone=2E Most likely, this tool doesn't
>> create any =2Egit/ORIG_HEAD file but =2Egit/HEAD is there=2E The error =
can
>> indeed be reproduced by renaming this =2Egit/ORIG_HEAD file while keepi=
ng
>> =2Egit/HEAD=2E In other words, it means it is not enough to check the
>> presence of =2Egit/HEAD to assume =2Egit/ORIG_HEAD exists as well=2E
>
>FWIW, It's not just custom git implementations, stock git doesn't ensure =
it's
>there either=2E I build a nightly VM image with Linus' kernel for postgre=
s
>testing, and as part of that I do a minimal clone:
>  git clone --single-branch --depth 1 git://git=2Ekernel=2Eorg/pub/scm/li=
nux/kernel/git/torvalds/linux=2Egit /usr/src/linux
>and then build the kernel=2E The build recently started failing like this=
:
>https://cirrus-ci=2Ecom/task/4648999113195520?logs=3Dbuild_image#L3121
>
>It's not a question of "--single-branch --depth 1" - ORIG_HEAD just isn't
>there in a new clone=2E Which makes sense, because there's no previous va=
lue for
>HEAD=2E

I merged the patch that stops looking for =2Egit files, as soon as I fix a=
 libperl feature test with CC=3Dclang I'll send a pull req to Linus to get =
rid of this =2Egit perf --version related regression=2E

- Arnaldo
>
>Greetings,
>
>Andres Freund