I might be onboard to switch to thiserror if that's the consensus of the team. We shouldn't just have thiserror in one place and string-based errors everywhere else, although I assume that wasn't your intention.

I can see the use for something like thiserror in libraries where the users of the library need to differentiate between the different errors. I'm not aware of cases where users of libwild need to do that though.

Or is it not about differentiating the error kinds, but just that you prefer this of raising errors?

Interested as to what @marxin and @lapla-cogito think

I'm inclined to say let's go ahead and merge this as-is. We can always change it later. I'm interested in other people's opinions as to how we should be doing error reporting. Perhaps a topic for our next monthly meeting.

I'm in favor of using thiserror when it makes the implementation cleaner, but I'm not sure how common such cases are beyond SFrame.