NetBSD Problem Report #57886
From www@netbsd.org Mon Jan 29 01:41:44 2024
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for <gnats-bugs@gnats.NetBSD.org>; Mon, 29 Jan 2024 01:41:44 +0000 (UTC)
Message-Id: <20240129014143.56BEC1A9239@mollari.NetBSD.org>
Date: Mon, 29 Jan 2024 01:41:43 +0000 (UTC)
From: campbell+netbsd@mumble.net
Reply-To: campbell+netbsd@mumble.net
To: gnats-bugs@NetBSD.org
Subject: lang/pythonN build suspends itself with SIGTTOU
X-Send-Pr-Version: www-1.0
>Number: 57886
>Category: pkg
>Synopsis: lang/pythonN build suspends itself with SIGTTOU
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: pkg-manager
>State: open
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Mon Jan 29 01:45:00 +0000 2024
>Originator: Taylor R Campbell
>Release: current
>Organization:
The NetTTY Foundation
>Environment:
>Description:
Now that readline is unconditionally included in the lang/pythonN packages, Python will unconditionally do silly things when stdin is a tty but stdout is not (e.g., redirect output to a file but don't redirect input, in a background job) -- under these circumstances it decides to initialize readline, and initializing readline makes it do TIOCGWINSZ, which is fine, and then TIOCSWINSZ, which suspends the process with SIGTTOU.
static int
get_tty_settings (int tty, TIOTYPE *tiop)
{
set_winsize (tty);
...
}
/* Dummy call to force a backgrounded readline to stop before it tries
to get the tty settings. */
static void
set_winsize (tty)
int tty;
{
#if defined (TIOCGWINSZ)
struct winsize w;
if (ioctl (tty, TIOCGWINSZ, &w) == 0)
(void) ioctl (tty, TIOCSWINSZ, &w);
#endif /* TIOCGWINSZ */
}
See https://mail-index.netbsd.org/tech-pkg/2024/01/03/msg028751.html and the thread leading into that for more detail.
>How-To-Repeat:
build python or things that use python at build-time in a background job with output redirected to a file and input from the tty
>Fix:
Workaround: run the build with input redirected from /dev/null.
Fix: Yes, please!
(Contact us)
$NetBSD: query-full-pr,v 1.47 2022/09/11 19:34:41 kim Exp $
$NetBSD: gnats_config.sh,v 1.9 2014/08/02 14:16:04 spz Exp $
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