From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: Getting complete Lisp backraces - the difficulty thereof Date: Sun, 14 Apr 2024 14:38:41 +0000 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="26195"; mail-complaints-to="usenet@ciao.gmane.io" To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sun Apr 14 16:39:35 2024 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1rw115-0006g3-HB for ged-emacs-devel@m.gmane-mx.org; Sun, 14 Apr 2024 16:39:35 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rw10Q-0003aw-6I; Sun, 14 Apr 2024 10:38:54 -0400 Original-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 ) id 1rw10O-0003ao-BC for emacs-devel@gnu.org; Sun, 14 Apr 2024 10:38:52 -0400 Original-Received: from mail.muc.de ([193.149.48.3]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rw10L-0006Nc-1N for emacs-devel@gnu.org; Sun, 14 Apr 2024 10:38:52 -0400 Original-Received: (qmail 10409 invoked by uid 3782); 14 Apr 2024 16:38:45 +0200 Original-Received: from muc.de (p4fe15ab7.dip0.t-ipconnect.de [79.225.90.183]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Sun, 14 Apr 2024 16:38:45 +0200 Original-Received: (qmail 26908 invoked by uid 1000); 14 Apr 2024 14:38:41 -0000 Content-Disposition: inline X-Submission-Agent: TMDA/1.3.x (Ph3nix) X-Primary-Address: acm@muc.de Received-SPF: pass client-ip=193.149.48.3; envelope-from=acm@muc.de; helo=mail.muc.de X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:317722 Archived-At: Hello Emacs. Why is it so difficult to get complete Lisp backtraces? It seems as though Emacs does its level best to discard large amounts of data from backtraces no matter what one does. This is frustrating. Why is there not a single variable to be set for this purpose? Instead, there are, perhaps, 20 - 30 controlling variables, all of whom seem set to discard information by default. These are things like print-level, eval-expression-print-leval, edebug-print-level, cl-print-depth, ert-batch-print-level, ert-batch-backtrace-right-margin, and on and on and on. These variables, collectively, are ridiculous. It is unreasonable to expect users to master them, the precious differences between them. Each of them, taken individually, may seem to be justified, but the collection as a whole is lamentable. Personally, I have given up trying to use these variables. I just go to the source code (e.g. ert.el), and spend time editing it to use debug-early rather than debug, setting variables to "infinite" where they allow it, and such things. I don't think it's possible to set ert to output complete backtraces, no matter what one does. By default one gets tiny amounts of data truncated to 70 columns wide, utterly useless for debugging. On a related note, some recent change has caused several copies of the 12-character string "\342\200\246" to be displayed in some lines of my backtraces. This appears to be an attempt to write U2026, the ellipsis, to my terminal. This is something I never asked for, neither the 12 character string nor the ellipsis itself, and I haven't been able to find any directions in NEWS or the ChangeLog to restore the old behaviour. The state of these things in Emacs is not good. -- Alan Mackenzie (Nuremberg, Germany).