Silence deprecation warning

[kornelski]

This method has been replaced by source()

[tailhook]

Thanks!

[dvic]

@tailhook I'm not sure the way this is usually handled but shouldn't we introduce a feature flag for also implementing source()? (for Rust 1.30 and above).

[kornelski]

Source would be nice, but I'm not sure how to deal with breaking changes and existing cause() syntax in quick-error.

Should quick-error's cause() generate source() implementation? What if lifetimes don't match?

Should the macro include a new, separate source() syntax?

[tailhook]

Yes, good question. Probably, I'd expect separate source() syntax. This would allow backwards compatibility with old rust, I think (i.e. don't add source method if it isn't mentioned in the macro).

[kornelski]

BTW, @tailhook I'd love to help, but the macro is intimidating. Could you add comments what each case in the macro does? What is the queue, chunks, and the bunch of upper-case keywords?