From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Noam Postavsky Newsgroups: gmane.emacs.bugs Subject: bug#36145: 26.2; Unable to "trigger another backtrace" Date: Sun, 09 Jun 2019 08:19:39 -0400 Message-ID: <87o9370x44.fsf@gmail.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="222773"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) Cc: 36145@debbugs.gnu.org To: Xu Chunyang Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Sun Jun 09 14:20:52 2019 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hZwod-000vo7-NC for geb-bug-gnu-emacs@m.gmane.org; Sun, 09 Jun 2019 14:20:51 +0200 Original-Received: from localhost ([::1]:35612 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hZwob-0000Tr-VT for geb-bug-gnu-emacs@m.gmane.org; Sun, 09 Jun 2019 08:20:49 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:39115) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hZwnq-0008KI-Vp for bug-gnu-emacs@gnu.org; Sun, 09 Jun 2019 08:20:04 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hZwnp-0001OV-UE for bug-gnu-emacs@gnu.org; Sun, 09 Jun 2019 08:20:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:40863) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hZwnp-0001OP-Qw for bug-gnu-emacs@gnu.org; Sun, 09 Jun 2019 08:20:01 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1hZwnp-0005Zg-Ka for bug-gnu-emacs@gnu.org; Sun, 09 Jun 2019 08:20:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Noam Postavsky Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 09 Jun 2019 12:20:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 36145 X-GNU-PR-Package: emacs Original-Received: via spool by 36145-submit@debbugs.gnu.org id=B36145.156008278721405 (code B ref 36145); Sun, 09 Jun 2019 12:20:01 +0000 Original-Received: (at 36145) by debbugs.gnu.org; 9 Jun 2019 12:19:47 +0000 Original-Received: from localhost ([127.0.0.1]:54407 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hZwnb-0005ZA-8m for submit@debbugs.gnu.org; Sun, 09 Jun 2019 08:19:47 -0400 Original-Received: from mail-io1-f45.google.com ([209.85.166.45]:34887) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hZwna-0005Yw-8w for 36145@debbugs.gnu.org; Sun, 09 Jun 2019 08:19:46 -0400 Original-Received: by mail-io1-f45.google.com with SMTP id m24so4833156ioo.2 for <36145@debbugs.gnu.org>; Sun, 09 Jun 2019 05:19:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:references:date:in-reply-to:message-id :user-agent:mime-version:content-transfer-encoding; bh=mEfRtWd+JwvYsyzjSoYQoTnufkmEnlVBajz1nAOZY2o=; b=aRltJXmVM9arTSTgty5atc1pHeSzCEOIqxTxf5wACUbhW9oOg4VKYO1qXO+Jc1amTJ 9D2Eq6ezxmgpk5Ypl9sCtKOHhlSwzl14KDNKqjKh5JTy55Z4W21Iwo7wMSch0X4tCwE3 h36kZXlPAqL38kJEvTAdq9m4enAO5eEsjF1LPVG5ocW0tgoT/9qF2yddL47AVV9eoyq1 lY9GEalhNMDXdDS0kIGw2BUdYWUxdjiBu2iH6+ftuh9YnUdt7la2CUoBfkbyQsQqyU2V DuxmFSPP8xXwouHsIy8zsKBkeYKBKrMBLH7UT8Yt1vQx1HJhUIh3bmx/y+Dpip9IPw8C 5gdw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:references:date:in-reply-to :message-id:user-agent:mime-version:content-transfer-encoding; bh=mEfRtWd+JwvYsyzjSoYQoTnufkmEnlVBajz1nAOZY2o=; b=cwvoODddXdF7SRiGxIBeodJ8kkme2UavDikpNhvsQnX63VIbjLN0FsUGDSBCjrOQFz f2KLRAq7mpVToB+a0QvzzJdkOcymjt3II1jn0A0Il/JMylQCSPozLb9KLo3HX7qhOp6F xWFEjw0Tf00DGCzxlaRtJCHTaztWpx6GW5QX4pyAeEhNkM22rcJntxHwYxyTL/pNYJco ss7nL5O93ijQBnm9fSahsvLLFxYkHGus3BlJr5bJolXWWKFtSRfmt5fy9YyYkzilJBai OvkxksTsFr44ww/fokeTq67GYwK/a4D32TPJ3H36giTvFcQ1LIDEISeKGc1TBjFhhQdI LCZA== X-Gm-Message-State: APjAAAV/1ViBO0DDaxDVcBGIoSEWCgLPrfnoet6AQWYJYHv3BRcFZmSh zYBIyoJ4vCd4njX0El+xFO8dvo2e X-Google-Smtp-Source: APXvYqynhmr5Rx3tMsxCcfJWaH2oww+4MuXLduFXZXKFv8/759hiP+5ber1SGklW8UBIz1UY0atNog== X-Received: by 2002:a6b:4f15:: with SMTP id d21mr14222010iob.210.1560082780488; Sun, 09 Jun 2019 05:19:40 -0700 (PDT) Original-Received: from minid (cbl-45-2-119-34.yyz.frontiernetworks.ca. [45.2.119.34]) by smtp.gmail.com with ESMTPSA id r62sm3467143ita.37.2019.06.09.05.19.39 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sun, 09 Jun 2019 05:19:39 -0700 (PDT) In-Reply-To: (Xu Chunyang's message of "Sun, 09 Jun 2019 15:18:37 +0800") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.51.188.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.org gmane.emacs.bugs:160273 Archived-At: Xu Chunyang writes: > (info "(elisp) Using Debugger") says > >> When the debugger has been entered, the =E2=80=98debug-on-error=E2=80=99= variable is >> temporarily set according to =E2=80=98eval-expression-debug-on-error=E2= =80=99. If the >> latter variable is non-=E2=80=98nil=E2=80=99, =E2=80=98debug-on-error=E2= =80=99 will temporarily be set >> to =E2=80=98t=E2=80=99. This means that any further errors that occur w= hile doing a >> debugging session will (by default) trigger another backtrace. > > Text before "This means.." is correct, but the conclusion seems > incorrect, to reproduce > > - emacs -Q > - M-: (/ 1 0) ;; enter the debugger > - M-: (/ 2 0) ;; just message the error, no another backtrace > > Am I misunderstanding "trigger another backtrace"? I think this is a documentation bug. You don't get another backtrace because inhibit-debugger is bound to t before invoking the debugger. This has been the case since Emacs 24.3 when inhibit-debugger was introduced [1: 45b82ad0eb]. But even before that, debug-on-error was in fact bound to nil when entering the debugger (and that has been the case since the initial revision of debug.el), so the documentation was always wrong (although it looks like you could trigger another backtrace with M-: because eval-expression would rebind debug-on-error according to eval-expression-debug-on-error, so the conclusion used to be correct, even though the explanation was always wrong). [1: 45b82ad0eb]: 2012-09-11 20:14:50 -0400 * src/eval.c: Add `inhibit-debugger'. https://git.savannah.gnu.org/cgit/emacs.git/commit/?id=3D45b82ad0ebedaa1b= 7094912e218bea1510c33feb