All error messages need to indicate which line of code in GDScript caused them to occur

[blackears]

One constant irritation working with Godot is the large number of error messages that indicate something going wrong in the C++ code and providing no indication which line in GDScript led to this happening.

I'm getting lots of error messages like

./core/templates/cowdata.h:167 - Index p_index = -1 is out of bounds (size() = 0).

and

core/math/basis.cpp:47 - Condition "det == 0" is true.
core/math/transform_2d.cpp:51 - Condition "det == 0" is true.

There is no other indication of what is causing these errors. My code base is pretty big now so I have little idea of where to look to start tracking these things down.

It would be really nice if the error reporting mechanism could indicate which GDScript line was the entry point which leads to these errors.

[Mickeon]

Sometimes this is just not possible because the errors are happening internally during the lifetime of the Object and not as a direct result of the developer's code. For the times where they can be caught (such as get_node() not finding any nodes at a path), the source of the error is shown. So I am not sure where you're coming from, exactly. These feel like bugs.

[AThousandShips]

Are you actually sure these are caused by script code? If they aren't caused by a call directly from scripting, like happening inside the engine instead, then they don't have a script line, so the first step here is to confirm that

Generally errors caused by calls from gdscript are logged correctly, this would be easier to debug with:

• Add a project setting to display a full stack trace for errors and warnings #963

[FabriceCastel]

I run into this problem constantly with my gdscripts, I can't tell you how many times I ended up with a largely unhelpful The axis Vector3 must be normalized error coming out of the (moderately complex) animation scripts I'm working on. I would hope for this to point me back to the line in my scripts that set the problem vector instead of leaving me guessing.

I can't recall the other errors I've seen off the top of my head but if I run into them again I'll make a note of it. At the end of the day, I as a dev don't care for the particulars of whether my scripts caused the error directly or indirectly. I expect the error to point at the line in my script that caused it either way. I understand it's non-trivial, but it's currently my biggest gripe with Godot and would be the main reason I'd end up switching back to Unity if I ever did.

[Calinou]

The error messages could at least mention the invalid value you passed though, which would make troubleshooting a lot easier. I've started working on this a while ago for select error messages but it's a long and tedious process to catch all scenarios where values should be logged.

An ideal example is Image's create_from_data() error message, which I improved in godotengine/godot#60126.

[AThousandShips]

Exactly 🙂

[Calinou]

Pull request opened: godotengine/godot#87300

[blackears]

It could also be helpful if the path to the node which is causing the error is printed, as well as any script attached to the object in case it is a Resource or non-Node causing the error. Just to give the person debugging it a bit more information. At the moment I have Godot telling me about arrays being indexed at invalid locations and I have no clue where to start looking.

[AThousandShips]

When possible absolutely