Yes. I'm not sure exactly what other response you'd expect from the author/maintainer of a library when they've already made a post encouraging other people to use it. ¯\_(ツ)_/¯

> when you could just use e.g., `.map_err(|source| Error::Opening { source, filename })`

That's not equivalent, as `filename` is a `&str` but becomes a `String` when stored in the error. SNAFU automatically calls `Into::into` for you, so the closest would be:

    .map_err(|source| Error::Opening { source, filename: filename.into() })

There's also the possibility of automatic construction of values (backtraces, location information, the current time, things captured from globals / thread locals, etc.)

Beyond `.context`, SNAFU also implements the `Error` trait (and associated methods like `Error::source`).

There's also convenience methods and macros to create leaf errors, those that originate in your code.

> obviously the `#[snafu(display(...))]` macros could just be moved into a `impl Debug for Error`

I'll assume you mean `Display`, not `Debug`. That also not quite true, as SNAFU offers a shorthand syntax that isn't yet in stable Rust:

    "Unable to read {filename}"

   "Unable to read {}", filename
   "Unable to read {filename}", filename = filename

All code could have been written by your own hand or otherwise inlined. Your response feels (needlessly) highly dismissive of another person's work.