According to the blog post https://blog.golang.org/experiment the design draft for printing frames is abandoned and they are on a look out for a better solution. I am not sure if the current implementation will stay. Do you have any more insights on this @stamblerre ?

My idea was to print the errors with log.Errorf("%+v", err)

Ah, I missed Russ's talk at GopherCon. I think I'm fine with using the features supported by x/errors as long as they are around, just to try them out.

I think we could make these changes quite simple and easy to revert because @ianthehat's telemetry work introduced a new way of logging errors. Supporting this behavior might be as simple as adding the %+v in a single place. Take a look at https://godoc.org/golang.org/x/tools/internal/lsp/telemetry/log and let me know what you think.

Just printing errors as %+v probably doesn't hurt in general. I suppose it's enough to change the format here:
https://github.com/golang/tools/blob/128824a23e7c038a341252700f1001ad29ef1988/internal/lsp/telemetry/log/entry.go#L46

Thanks for the hint :) I'll try it out locally. Any hint on how to reliably cause an error?

Something like messing with the name of the package, adding an import that doesn't exist, completing something that's not declared - these would all likely cause errors to be logged.

Change https://golang.org/cl/189344 mentions this issue: internal/lsp: add additional information when logging errors