Compiler panic when try to execute incorrect regex!

[defuz]

My code:

#![feature(phase)]
#[phase(plugin)]
extern crate regex_macros;
extern crate regex;

static R : regex::Regex = regex!("-|+");

fn main() {
    println!("Hello, kich!");
}

What I do:

$ rustc src/main.rs
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'Tried to unwrap non-AST item: Bar', /Users/rustbuild/src/rust-buildbot/slave/nightly-mac/build/src/libregex/parse.rs:161

My rust version:

$ rustc --verbose --version
rustc 0.13.0-nightly (96a3c7c6a 2014-12-23 22:21:10 +0000)
binary: rustc
commit-hash: 96a3c7c6a051ab2f5fc01fe9e686f7fffcc87c61
commit-date: 2014-12-23 22:21:10 +0000
host: x86_64-apple-darwin
release: 0.13.0-nightly

I know that my regular expression is wrong, but I think that the compiler panic in this case it is not normal.

[andrewyli]

"Tried to unwrap non-AST item: Bar" error probably comes from the |+. Make it |\+, I think.

[defuz]

@EchoAce I understand what the problem with this code, but I think this is not acceptable behavior of the compiler. (Initially, the regular expression was much larger)

[andrewyli]

You're probably right; the non-AST message seems appropriate but the bug warning doesn't.