sdkerrors: make Wrap compatible with Go standard library errors extractors

[odeke-em]

Coming here from tip 5903586 and PR #7770 in which I tried to invoke

sdkerrors.Wrap(sdkerrors.ErrTxDecode, err)

where err was an io.UnexpectedEOF, and then later I tried to do

errors.Is(err, io.UnexpectedEOF)

but it fails because sdkerrors stringifies content, thus to perform the check I had to resort to a hack

require.Contains(t, err.Error(), io.ErrUnexpectedEOF.Error())

This issue isn't critical, but just a nice-to-have.

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[alexanderbez]

You mean sdkerrors.Wrap(sdkerrors.ErrTxDecode, err.Error()), as you're not wrapping the ErrUnexpectedEOF, you're wrapping ErrTxDecode.

Regardless, I believe @ethanfrey brought over the errors pkg from Weave so we can expose stracktraces? I would be ideal to just use the stdlib wrapping while keeping our ABCI error types.

[ethanfrey]

Yeah, I wanted something like pkg/errors - the stacktraces are very useful - that also contained the abci code info. This started from what I did at weave and evolved a bit to make it fit the sdk structure. It can evolve again. However:

sdkerrors.Wrap(sdkerrors.ErrTxDecode, err) is wraping sdkerrors.ErrTxDecode with the error text.

err = sdkerrors.Wrap(io.UnexpectedEOF, "Some useful context") should later match on errors.Is(err, io.UnexpectedEOF)

I haven't touched this in about a year, but my guess is usage error (which needs a better API/docs). The main point is if you wrap std errors, you have no abci code and it all ends up as 1 - Internal (and redacted at the abci boundary). You are supposed to use a proper sdkerror and add the context and compare to that - this will have a proper error code at the abci boundary.

nb: I have no idea if anyone ever uses those error codes in any client, but that is a different story

[ethanfrey]

Also, there is sdkerrors.Is() which does the same compare - the std versions came after this code, and I am happy to adjust them to be compatible if there is a way to do so without breaking the fundamental functionality

[tac0turtle]

this was done by Aaron in the new errors module.