Adopt stacked error to snafu

[waynexia]

Hi @shepmaster! I'm the author of that post on hackernews. I'm thrilled to see snafu and this mechanism being discussed so much.

Snafu has no doubt helped us a lot in organizing complex error variants and saved time on debugging. I'm wondering if we can contribute it to the upstream (here) and let people use and evolve it together. From my side, I have two concrete motivations for doing this, (1) implementing it out of snafu requires some hacking code and (2) pushing it to a more common location can further accomplish the error stack, the current stack will become chaos when getting through different error libs from different dependencies.

This might not be a trivial change. I'd like to hear some suggestions and/or feedback from your side on whether this is viable and if so how can we get started ❤️