[LLDB][VSCode][Mac] not updating Dave

[janhenhan]

Hello!

Thank you very much for this project! It's exactly what I was hoping for.

I tried getting it running on my Mac. While I managed to have a Dave window open and show the current original content of a buffer, it does not update e.g. as I let the debugger run and have the contents of the buffer change. Also, neither concat nor freeze options have any effect. The window only shows the status of the buffer when I ran the 'dave show buffer' command.
This limits the usability quite drastically.

I am not exactly sure how one would debug the execution of Dave's code. Any pointers on what could be tried to get Dave to update the plots would be much appreciated.

Thanks!

[maxmarsc]

Hi ! Great to know you like this tool.

Some context & tips

First things first, I don't own a Mac so I won't be able to replicate your issue on my machine. But we can try to solve it anyway.

In short, different IDEs have different ways to call the debugger, different ways to communicate with the debuggers, and different debuggers have different ways of calling the python code. Dave's code is running on two separate process, on on the debugger's python interpreter, one independent handling the GUI.

All these constraints unfortunately makes it really hard to have a reliable way to debug Dave's code. You could try inject some code in Dave's code that prints out the PID of it, then attach a python debugger (pdb, debugpy...) to it. I suspect for such a bug you'd be interested in the debugger's process side of thing. Let me know if you wanna go this route so I can help you.

But first you can try enabling debug logging. Export DAVE_LOGLEVEL=Debug before opening VSCode (not from vscode terminal, unless you start lldb there). This should give you more verbose logging which you can paste me so we can look at it.

---

What the bug probably is

I had similar issues when working with CLion and LLDB, I suspect the bug is related. In short the IDE internally store the debugger state, instead of relying on LLDB's internal tooling. They communicate with LLDB using mi-commands, a higher-level interface which does not provide the same capabilities as the APIs Dave is using.

Therefore it is extremely hard for Dave to follow closely the IDE behaviour. I tried reaching to VSCode and CLion devs but they told me I'd had to deal with it myself.

I ended thinking the only way to get full compatibility with IDEs I would need to create dedicated plugin for each IDE: VSCode, CLion, Xcode... I simply didn't had time yet, especially for VScode since I don't know JavaScript which is required for vscode plugins.

If you wish to go down this path I'd be happy to help though.

Let me know what you think, sorry for the long post haha

[janhenhan]

Thank you for those details, Maxmarsc!

Since you mention the details of the IDEs as a possible source of issues, it may be worth noting that I use the VSCode extension codelldb.
I did set DAVE_LOGLEVEL to debug, but I am not sure if the output will help us much. Here's the output from the Debug Console:

(lldb) # --- DAVE BEGIN ---
(lldb) command script import ~/.dave/lldb_init.py
Stop hook #1 added.
DEBUG: Detected debugger : ServerType.LLDB
DEBUG: Trying to import custom containers from /someactualpath/examples/custom/__init__.py
DEBUG: Creating lldb.SBListener
DEBUG: Creating EventHandler thread
INFO: [dave] Successfully loaded
(lldb) # --- DAVE END ---

running dave show buffer will then lead to:

DEBUG: Building buffer from type |juce::AudioBuffer<float>|
INFO: Added buffer : 5
DEBUG: Building buffer from type |juce::AudioBuffer<float>|
DEBUG: Building &buffer from type |juce::AudioBuffer<float>|
DEBUG: Building  from type |juce::AudioBuffer<float>|

In the LLDB output window I can see

Launching adapter
liblldb: /Applications/Xcode.app/Contents/SharedFrameworks/LLDB.framework/Versions/A/LLDB
environment: {}
settings: { evaluateForHovers: true, commandCompletions: true }
DEBUG: Received new entities : 5
DEBUG: Received oos update : 5

[maxmarsc]

Ok great. What I'm mostly interested about is the logging when hitting a new breakpoint after running dave show ***. Also the output when clicking Freeze and Concat please.

If you have screenshot of the debugged code & the corresponding GUI state that would be extra helpful.

codelldb is probably gonna make the VScode plugin fix harder to make haha, but we're not there yet.

[janhenhan]

Thank you!
What I posted above is actually all the output I get when running dave show where in my case the array is called buffer. I can't see any additional output when clicking Freeze or Concat.

[janhenhan]

I forgot to mention I actually also get the same non-updating behavior when running lldb CLI.

[maxmarsc]

Do you see any additional output when calling/clicking continue and hitting a new breakpoint ?

I you have the same non-updating behaviour on LLDB from the CLI then let's focus on the CLI part, it will be easier to debug.

Could you please provide a screenshot of your VSCode + DAVE GUI before and after hitting continue please ? I'm interested in the source code (if you can show parts of it of course) lldb console.

[janhenhan]

I wanted to send you a screenshot of your own JUCE example and there actually got some different behavior in a different VSCode workspace. There, I at least had a meaningful error message: In this function call you call a function that takes two arguments with three.
Once I changed that, I got an update to the Dave display in the example. Why it behaves different in my actual project in a different VSCode workspaces is a topic for a different day maybe.

[maxmarsc]

Yes I just identified this bug yesterday haha, a fix is on the way with a few changes. In the meantime you can use your local fix.

So after this fix does your issue still occurs in your code ? Still no error message whatsoever ?

[maxmarsc]

I wanted to send you a screenshot of your own JUCE example and there actually got some different behavior in a different VSCode workspace. There, I at least had a meaningful error message: In this function call you call a function that takes two arguments with three. Once I changed that, I got an update to the Dave display in the example. Why it behaves different in my actual project in a different VSCode workspaces is a topic for a different day maybe.

This subtle bug has been fixed in the v0.11.0 release. Please update and let me know :)

[janhenhan]

I tried updating to latest main (v0.11.0), but my lldb's python is choking on the python 3.10 syntax you are using in the server's code here

[maxmarsc]

Erf, yes this is supposed to happen. DAVE officially require Python>=3.10 to run.

Would you mind sending me the version of lldb your VSCode extension makes you use please ? It's probably a bit outdated.