internal compiler error preventing servo from compiling on OS X 10.8

[bdaehlie]

Compiling servo fails on OS X 10.8 due to an internal compiler error.

rust: task failed at 'index out of bounds: the len is 0 but the index is 0', /Users/josh/src/mozilla/rust/src/librustc/middle/trans/_match.rs:1283
error: internal compiler error: unexpected failure

This happens with current rust trunk, usually while compiling "servo-gfx".

[sethfowler]

Here's a log with RUST_LOG=rustc::middle::trans: https://gist.github.com/sfowler/5485802

[ILyoan]

This also appears on linux

[jld]

rust: ~"Representing: core::result::Result<@?,()>"

I wonder if I did something subtly wrong with pattern-matching on nullable-pointer enums (d0451ee).

[jld]

In answer to my own question: Yes, I did.

[jld]

This test case is smaller than servo:

pub fn main() {
        match Left(@17) {
                Right(()) => {}
                _ => {}
        }
}