Error extensions

[strange island]

Hey @neon sage 👋 I'm having an issue with dag.Error, in particular the extensions here: https://github.com/dagger/dagger/blob/006ba588ed35fea738a9399e43ef7e393b68ed88/core/error.go#L36-L42. Are we using what's generated here somewhere?

Since the values are stored in JSON, it's creating the extension values with encoded JSON, which doesn't match how SDKs are converting to dagger.ExecError. We need to unmarshal into any, do you see any problem with that?

[strange island]

I also want to talk about exception traces. I could add an extension for the exception trace but it won't be used anywhere, right? I still need to print it to stderr otherwise users won't be able to see it in TUI/Cloud.

[neon sage]

Ah I have a fix for this in my errors PR already, I ran into it too

[strange island]

I see, yes: https://github.com/dagger/dagger/pull/10512/files#diff-3e43f37e3bd6fd18460293f742ab16cce430da2a6850c97ed0c59e7abf6ff943

[neon sage]

Correct - we actually show them generically to LLMs but don't show them in the UI. I think we should be careful not to just show all fields+content to the user though, otherwise we're back where we started (redundant/verbose info being shown). So maybe we could look specifically for a backtrace field for example

[strange island]

Yeah, that's what I was after.

Could have a sort of button (like reveal noisy spans), but only on the function that created it because it's going to be propagated through extensions.

Or maybe show only with --debug.

[neon sage]

Yeah, a generic thing for showing them would be good, sort of like seeing all the span attributes too (someday)

As long as it's behind a toggle, or we show collapsed individual fields, etc

(I'm mostly thinking Cloud here but some TUI analogue would be good too if we can find it)