[Bug] Different behavior when hooking the Context on stable vs. nightly

[TimDiekmann]

Describe the bug

On stable, downcast_ref is used for the hooks, on nightly request_ref and request_value is used. For attachments, this is the same as attachments only provide themself, but for contexts do not provide themself. When installing a hook for e.g. io::Error and use io::Error as context, the output is different:

stable:

invalid input parameter
├╴test.rs:10:18
╰╴invalid input parameter

nightly:

invalid input parameter
╰╴test.rs:10:18

To reproduce

use std::io::{Error, ErrorKind};

use error_stack::Report;

fn main() {
    Report::install_debug_hook::<Error>(|error, ctx| {
        ctx.push_body(error.to_string());
    });

    let report = Report::new(Error::from(ErrorKind::InvalidInput));

    println!("{report:?}");
}

Expected behavior

The output should be the same and stable and on nightly.

Rust compiler

1.63 and 1.65.0-nightly (2022-08-26)

Host

aarch64-apple-darwin

Target

aarch64-apple-darwin

Version

cf5d85e

Features

all

Additional context

As a Context does not provide itself, the same behavior should be emulated on stable as well. As provisioning is not supported on stable, a Context frame can simply be ignored.

The other solution would be to provide the context frame as well.