Chapter 09, Part 1, outdated panic explanation

[Oxygels]

In chapter 09-1, available here:
https://doc.rust-lang.org/book/ch09-01-unrecoverable-errors-with-panic.html

An explanation of the panic seems outdated.
The book refers to an error in a source file in core (here slice/mod.rs) but the error message instead refers to the caller (which is the indexing operation) in main.

The panic :

$ cargo run
   Compiling panic v0.1.0 (file:///projects/panic)
    Finished dev [unoptimized + debuginfo] target(s) in 0.27s
     Running `target/debug/panic`
thread 'main' panicked at 'index out of bounds: the len is 3 but the index is 99', src/main.rs:4:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

The explanation:

This error points at a file we didn’t write, libcore/slice/mod.rs.
That’s the implementation of slice in the Rust source code. The code that gets run when we use [] on our vector v is in libcore/slice/mod.rs, and that is where the panic! is actually happening.

I assume this is due to the introduction of #[track_caller].

[carols10cents]

Thanks! This is a duplicate of #2550, which was fixed in 2250f51.