Use Failure crate to enhance error handling

[0x7CFE]

Failure crate reflects new approach to error handling in Rust.

It natively supports backtraces, error downcasting, and is backward compatible with io::Error through blanket impl. Detailed information, as well as various use cases may be found in documentation.

I think, we may consider migrating to this crate once it became stable enough.

[debris]

It looks interesting. Do you know if it supposed to be complementary to error_chain or is it supposed to be a replacement for it?

[0x7CFE]

Failure was intentionally designed to be backwards compatible with std. If I understood correctly, it may operate with other error types within a single crate without much pain.

Regarding error_chain interoperability, I believe, it would be supported someday. Right now it may be achieved using the standard Error trait, but maybe later we would have some specific options.

The very same question was asked on recent Bay Area meetup. You may check the video at 1:43:30.

[0x7CFE]

It is expected, that Failure would hit 1.0.0 on March 15.

I think it's a good time to reconsider, whether we want adopting it in the near future (at least for a new code).

[folsen]

A month later it is still not 1.0, I think we should consider it for new code, but closing this issue until it is in a more stable place.