% rustc src/main.rs -C debuginfo=1
warning: this expression will panic at run-time
 --> src/main.rs:4:19
  |
4 |     let element = a[index];
  |                   ^^^^^^^^ index out of bounds: the len is 3 but the index is 10
 % rustc src/main.rs -C debuginfo=2
 % rustc src/main.rs               
warning: this expression will panic at run-time
 --> src/main.rs:4:19
  |
4 |     let element = a[index];
  |                   ^^^^^^^^ index out of bounds: the len is 3 but the index is 10

% rustc --version --verbose
rustc 1.24.1 (d3ae9a9e0 2018-02-27)
binary: rustc
commit-hash: d3ae9a9e08edf12de0ed82af57ba2a56c26496ea
commit-date: 2018-02-27
host: x86_64-unknown-linux-gnu
release: 1.24.1
LLVM version: 4.0