I am a big fan of Julia as a programming language, but the lack of a decent debugger keeps turning me away every time I seriously consider changing to it. Now last time I tested the debugging environment out was last summer, and I haven’t really done anything with Julia since or kept up on any potential updates. So I’m writing this, wondering whether the debugging environment have changed in the last year or so? (My own search didn’t reveal anything, and I didn’t see anything in the Juliacon presentations this year about it either) Or whether there is any future plans for making an IDE with full debugging? What I am looking for is an IDE environment like: Pycharm, visual studio, matlab or delphi, which are all excellent in their own way.

Please please please don’t go there again. There has already been huge threads of people talking past each other, with one side saying (I’m caricaturing) debuggers are for people who don’t know how to code and the other side saying that julia has to have a state-of-the-art debugger or “nobody will use it”. Some people can’t live without debuggers, some don’t see the point. That’s a fact, let’s move past this, please. Many people find debuggers useful. Everybody acknowledges that julia’s debugging solutions are not perfect and far from the experience provided in several IDEs, but that writing really seamless debuggers is a large, thankless work (which is particularly difficult in Julia due to intrinsic characteristics of the language) which is unlikely to happen anytime soon unless 1) somebody suddenly decides to write one 2) somebody suddenly decides to give a few thousand dollars to pay someone else to do it. In the meantime, there is a debugger that works well although with a performance hit, and solutions like infiltrator/exfiltrator that provide an alternative debugging workflow.

Let’s not lose sight of the fact that we already HAVE Julia debuggers. Not just one, several! Are they perfect? No. But they are already useful.

Several debuggers already exist, with most of the features you expect from a modern debugger, yet with some weaknesses. There is active, though long-term, work going on to improve them. There are alternative workflows and programming styles well-suited to the Julia language that alleviate some (but not all) of the need for debuggers. Is that close to a reasonable summary?

[image] DNF: There are alternative workflows and programming styles well-suited to the Julia language that alleviate some (but not all) of the need for debuggers. I’m skeptical about the “but not all” point. I’d be interested to know how many people in the julia community that work on big code bases actually actively use debuggers. There are very productive people I know who are working on very big, complicated code bases that never use or even installed a debugger. To me, that indicates rather strongly that there are code styles that make these things unnecessary (granted, changing coding practices is hard!)

I didn’t intend to get into a debate, rather to summarize, but I’ll just say I like debuggers for understanding code, not necessarily for debugging it. Furthermore, some of us need debuggers specifically because we’re not master developers.

Hmm… this discussion sounds familiar :thinking:

[image] mancolric: [image] kristoffer.carlsson: Which people are you addressing with this post? To the developers (some of you, right?) I am not sure if you are aware of this, but a lot of the progress on Julia, its standard libraries, and the package ecosystem just happens because people contribute work. While some people work on Julia full time, the divide between “developers” and “users” is not as significant as other languages. In other words, if you really want something and it does not seem to be happening, the realistic alternative is to start coding or pay someone to do it. Exhortations along the lines of how “Julia won’t be competitive unless you do what I ask for” pretty much fall on deaf ears.

I fully agree with mancolric. I think my colleagues and I are one of Julia target audience. We suffer every day from the two language problem. We use mainly Matlab and Python to develop and test new algorithm. And if we are successfull these algorithm/scripts are transfered to C/C++/C# to run fast. This is really expensive! We would tremendously benefit from using Julia. We don’t know the solution when we start. We are scientists (mainly physicists), we are not programmer or computer scientists. Our approach is more try and error. But for this work we need a fast and easy debugger like in Matlab. I think there are a lot of people and they have different use cases for Julia. And I see that it is important to understand, that everybody have other needs. Unfortunately at the current state, I will not have a chance to convince my colleagues to even try Julia because of the debugger. I am fully aware that Julia should be give and take. We could contribute in the form of librarys and/or algorithms and we do … unfortunately not in the Julia ecosystem.

As is often the case with these generic discussions, it’s hard to find out what people actually want when they say “julia needs a good debugger such as Matlab/Python/Java/C++/etc.”. Just saying “good debugger” doesn’t tell us anything about your actual needs and what’s wrong with the current e.g. Debugger.jl though. For example (and inspiration): Is It too slow? You’re debugging, that’s a different type of execution than normal, so slower run time is expected (for any language, not just julia). Are you missing breakpoints? Debugger.jl has those, and as far as I know, they’re also exposed via Visual Studio Code and Juno. Do you want to live-inspect variables at full-speed runtime execution? This also kind of works in compiled mode of Debugger.jl, but has its limitations (as with every debugger) Well… Why didn’t you just tell us about this? As you say yourself, everyone codes differently, so not everyone has the same perspective and experiences the same pain points. Maybe the pain points you experience aren’t actually a problem of the lack of features of the Debugger or julia itself, but because you’re wielding a fencing sword like a heavy two-handed broadsword and don’t know how to wield a fencing sword. Sure, it will do the job, but only subpar. If that’s the case, we’ll be glad to give advise on how to wield the sword, provided you can tell us what you really want to do. Lastly, the vast majority of people on this forum aren’t computer scientists either. They’re biologists, physicists, mathematicians, astrologists, economists and many more I don’t know the occupational title of. Their backgrounds certainly don’t include a theoretical understanding of the intrinsics of the compiler or the language itself, they’ve just taken the time to understand the tool they’re trying to use. They’ve asked questions if they didn’t understand how to do something, when things didn’t work because they where coming from another language, when some behaviour didn’t make sense to them, or when they wanted to get a second opinion on whether or not their approach makes sense in julia. This forum is full of those questions, and I wouldn’t want to have it any other way. The important thing is, whenever they hit a roadblock, they talk in specifics about what doesn’t work/should work - “the debugger is not good” is not specific.

On a side-note, I think if you use the debugger in julia and think “but my code runs slow now” you shouldn’t think “I wish I was back in Matlab, where I didn’t notice the difference between debugging and not debugging and where I had to rewrite the code to make it fast and then verify that the rewrite is correct”, but should think more like “Oh nice, so once I fix this bug with a small reproducer I’m done and it’s already fast!”. That’s how I think about it anyway.

Debugger status and future plans?

Community

kevbonham October 8, 2020, 10:56pm 87

Hmm… this discussion sounds familiar

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Debugger status and future plans?

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