From debbugs-submit-bounces@debbugs.gnu.org Tue Mar 08 14:07:33 2022 Received: (at 53355) by debbugs.gnu.org; 8 Mar 2022 19:07:33 +0000 Received: from localhost ([127.0.0.1]:57950 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1nRfBE-000405-OJ for submit@debbugs.gnu.org; Tue, 08 Mar 2022 14:07:33 -0500 Received: from eggs.gnu.org ([209.51.188.92]:43640) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1nRfBD-0003zo-5V; Tue, 08 Mar 2022 14:07:31 -0500 Received: from [2001:470:142:3::e] (port=43956 helo=fencepost.gnu.org) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nRfB7-0002gJ-Uf; Tue, 08 Mar 2022 14:07:25 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=MIME-Version:In-Reply-To:Date:References:Subject:To: From; bh=gIMcQZTk4tANSlYXDYlIuIGOZoc6mjjqqpjcBQjwfjg=; b=lSB30T2tKpYe+LaZ11Li HfMkG1yNF4evjI3PI0lHwfTXtqkmLKowllZRFm1/vSoLYLSVUWBN0zqehuJ049ibqyEffLc+Ch4oj ojLhiNQWy12Wfiq5D6A5+uIo7N0X9fVfqBKqTi75A7h/MzWN8NSeOpeheD3QRj2pQzTXjux/wucR4 9Nzilr2Jp7Pnb3GuEQEjw0ZyvQQohZKJQnZE+aGv3OGdGHiPz/E7z/PUt5ZJ39AwnITnzUCo5Duqa uhC7cYfbYzu9M+kAtct1l8I2PAHusjXqI8Ilpy4xMHbHpAZmPacI1jkURol+KsxqbgoIblPmY9sy5 jlUn/e+oStM9cA==; Received: from 91-160-117-201.subs.proxad.net ([91.160.117.201]:49420 helo=ribbon) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nRfB6-0003Td-0s; Tue, 08 Mar 2022 14:07:25 -0500 From: =?utf-8?Q?Ludovic_Court=C3=A8s?= To: Chris Marusich Subject: Re: bug#53355: guix shell --check: confusing error message References: <87h7a08kub.fsf@gmail.com> <87lez5td4n.fsf@gnu.org> <87sftc4osu.fsf@gmail.com> <87h79slysd.fsf@gnu.org> <87sft13dyv.fsf@gmail.com> <874k59d802.fsf@gnu.org> <87wnhy2w73.fsf_-_@gmail.com> <878rudzsmv.fsf@gnu.org> Date: Tue, 08 Mar 2022 20:07:21 +0100 In-Reply-To: <878rudzsmv.fsf@gnu.org> ("Ludovic =?utf-8?Q?Court=C3=A8s=22'?= =?utf-8?Q?s?= message of "Mon, 14 Feb 2022 10:47:52 +0100") Message-ID: <87ilso461i.fsf_-_@gnu.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Spam-Score: -2.3 (--) X-Debbugs-Envelope-To: 53355 Cc: 53355@debbugs.gnu.org, 51466@debbugs.gnu.org X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -3.3 (---) Hi Chris, Did you have a chance to look into it? https://issues.guix.gnu.org/53355 TIA. :-) Ludo=E2=80=99. Ludovic Court=C3=A8s skribis: > Hi Chris, > > Thanks for debugging this! > > Chris Marusich skribis: > >> From c3eea81846ae71a246e6b592be74062f4bf26474 Mon Sep 17 00:00:00 2001 >> From: Chris Marusich >> Date: Sun, 13 Feb 2022 14:15:14 -0800 >> Subject: [PATCH] environment: Prevent PS1 from clobbering output in 'che= ck'. >> >> Fixes: . >> >> * guix/scripts/environment.scm (child-shell-environment): In the script >> executed the child shell, set PS1 to an empty value and then echo three >> sentinel lines to try to "flush" the original PS1 value before printing = the >> environment variables. In the parent process, read and discard all line= s up >> to and including the last sentinel line. After that, read the remaining= lines >> as usual. > > [...] > >> + ;; Why print "GUIX_FLUSH" a few times? We are trying to "flush" the >> + ;; original PS1 value to the port so we can read it (and discard it) >> + ;; before we start reading the environment variables from the port.= If we >> + ;; don't do this, the original PS1 value can sometimes get interlea= ved >> + ;; into the output, which interferes with our parsing logic. It's = a hack, >> + ;; but in practice it seems to do the job. If you know of a more g= raceful >> + ;; solution, please implement it! See: https://issues.guix.gnu.org= /51466 >> + "PS1=3D; for i in 1 2 3; do echo GUIX_FLUSH_$i; done; \ >> +env || /usr/bin/env || set; echo GUIX-CHECK-DONE; read x; exit\n") > > So you confirm that a single =E2=80=9Cecho=E2=80=9D is not enough, right? > > Perhaps we should unroll the =E2=80=98for=E2=80=99 loop for portability, = to be on the > safe side. Initially I tested with Bash, Zsh, and Fish: > > https://issues.guix.gnu.org/51285#0-lineno49 > > I think Fish has a very non-POSIX syntax, hence the suggestion to avoid > =E2=80=98for=E2=80=99. > > I realized that setting PS1 could interfere with the logic below that > checks for PS1. And since it doesn=E2=80=99t seem to help, perhaps we can > remove =E2=80=9CPS1=3D;=E2=80=9D? > > Thoughts? > > Sorry to answer with yet more questions! > > Thanks, > Ludo=E2=80=99.