From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Olivier Dion via "Developers list for Guile, the GNU extensibility library" Newsgroups: gmane.lisp.guile.devel Subject: A Guile debugger workgroup? Date: Tue, 29 Nov 2022 12:21:20 -0500 Message-ID: <87edtlptgv.fsf@laura> Reply-To: Olivier Dion Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="24756"; mail-complaints-to="usenet@ciao.gmane.io" To: guile-devel@gnu.org Original-X-From: guile-devel-bounces+guile-devel=m.gmane-mx.org@gnu.org Tue Nov 29 18:22:04 2022 Return-path: Envelope-to: guile-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 1p04J1-0006Da-7v for guile-devel@m.gmane-mx.org; Tue, 29 Nov 2022 18:22:03 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1p04Ia-0001nF-TI; Tue, 29 Nov 2022 12:21:37 -0500 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 1p04Ia-0001n7-5h for guile-devel@gnu.org; Tue, 29 Nov 2022 12:21:36 -0500 Original-Received: from smtp.polymtl.ca ([132.207.4.11]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1p04IY-0004Z6-08 for guile-devel@gnu.org; Tue, 29 Nov 2022 12:21:35 -0500 Original-Received: from localhost (modemcable094.169-200-24.mc.videotron.ca [24.200.169.94]) by smtp.polymtl.ca (8.14.7/8.14.7) with ESMTP id 2ATHLKNj009843 for ; Tue, 29 Nov 2022 12:21:25 -0500 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp.polymtl.ca 2ATHLKNj009843 X-Poly-FromMTA: (modemcable094.169-200-24.mc.videotron.ca [24.200.169.94]) at Tue, 29 Nov 2022 17:21:20 +0000 Received-SPF: pass client-ip=132.207.4.11; envelope-from=olivier.dion@polymtl.ca; helo=smtp.polymtl.ca X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: guile-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Developers list for Guile, the GNU extensibility library" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guile-devel-bounces+guile-devel=m.gmane-mx.org@gnu.org Original-Sender: guile-devel-bounces+guile-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.lisp.guile.devel:21487 Archived-At: Greetings Guilers, There's been a discussion on the state of debugging with Guile on the guix-devel mailing list. Here's the relevant link if you want the full discussion: which is a reply to . I'm going to resume what I've gather here. I've mainly cutoff Guix related stuff. I'm also putting names here for the sake of clarity. I think it would be interesting to have more inputs from the Guile users at large -- outside of Guix -- on that topic. From my personal experience and the echo I get back from other users, the debugging experience in Guile is frustrating. Things I've gather in this reading and on the IRC with other users. This is by no way a wish list, but simply ideas to improve the debugging experience: 1. Documentation on debugging should be improved. e.g. The `pk` procedure. 2. A tutorial on how to debug a project with `pk` and the REPL. 3. A single-step (instruction and line) debugger. 4. Integration in GDB. e.g. GDB could insert breakpoints in Scheme code. 5. Maybe not make a debugger with a paradigm for language like C but instead take inspiration from other Scheme implementation like Racket. Resume start here: zimon: Preparing some materials for introducing Guile to GuixHPC folk, I am trying to collect some tips and, if I am honest, the debugging experience with Guile is really poor; compared to others (as Python). For example, DrRacket provides an easy and nice user experience Well, IMHO, we are somehow suffering from some Guile limitations and improvements in this area are an hard task. Maxim: I also agree! It's hard to convince people to pick Guile for their project when there is: 1. Lack of a debugger that can break and step anywhere in your source code =20=20=20=20=20 2. Lack of debugger integration to an IDE (it's not even integrated into Emacs) Perhaps we should assemble a Guile debugger workgroup that'd review what's broken, what's missing, what can be borrowed from other Scheme or languages for inspiration Ludo: Well, Guile has a debugger that lets you do that [...] Geiser is not Visual Studio=E2=84=A2 but it does a good job. Also, [...] I mentioned before that I almost never use breakpoints on Guile code [...] because it=E2=80=99s rarely the right tool for the job. I believe this is largely due to (1) writing functional code, and (2) doing live programming at the REPL. Why would you use breakpoints when you can just call the relevant procedures on some input to see how they behave? So I think you won=E2=80=99t convince people to pick Guile for their proj= ect by selling it as a C/C++/Python drop-in replacement. Guile is about functional programming and live coding so the set of tools differs. Despite what I wrote, I think it=E2=80=99s a good idea. I suppose inspir= ation would come from other Schemes, in particular Racket, and perhaps from other live-coding systems (Common Lisp, Smalltalk, etc.), rather than from Python or C. Zimon: Maybe I am wrong or miss some Guile features. From my experience, the issue is not the way that the information is presented or how we interact with it (Geiser or else) but, instead, the issue is the availability of such information. Well, so you are using the good ol=E2=80=99 way putting =E2=80=99pk=E2=80= =99 here or there, right? One thing when debugging is to inspect the current state of the program; [...] And, =E2=80=99pk=E2=80=99 is the poor man breakpoint. = :-) Racket is an example of functional programming and live coding. Haskell is another; it is functional programming and if I might, I would recommend to give a look at the interactive GHCi debugger Maxim: When searching for how the debugger work in the Guile Reference info manual, I also don't find anything useful: only the gut of the debugging API of the Guile VM appears to be documented ("Debugging Infrastructure"), so documentation is another place that could be improved, with some examples and pro tips for real life, practical debugging with Guile. Ludo: I think we should identify scenarios where things don=E2=80=99t work as expected, and then turn them into bug reports, documentation issues, or any other concrete action we should take. [...] that brings us back to Maxim=E2=80=99s suggestion of starting a debugger workgroup. Attila: [C]oming from common lisp [...], [I] think the lowest hanging fruit in the guile debugging experience is making sure that backtraces are not cut short when printed. [T]his is regularly causing me frustration when all i need to make progress is in the cut off part of the backtrace, and the code in question is in a part of the codebase that i can't easily change to add some good old printf's. Joshua: Just my 2 cents, I always thought that the elisp debugging experince is super user friendly and awesome! M-x edebug-defun RET function-name RET And you are golden! It would be awesome if guile could offer something as seemless. Csepp: Can we also get a profiler like Python's Scalene? I'm pretty sure there are some performance bottlenecks it could help identify, both in Guix and in Guile itself. --=20 Olivier Dion oldiob.dev