ICE 'index out of bounds' in extra::ebml

[SimonSapin]

Upgrading Servo to today’s Rust gives (after a few fixes) an ICE:

% RUST_LOG=rustc=1 make -j8
compile: servo
task <unnamed> failed at 'index out of bounds: the len is 52757 but the index is 52757', /home/simon/projects/servo/src/compiler/rust/src/libextra/ebml.rs:119
error: internal compiler error: unexpected failure
note: the compiler hit an unexpected failure path. this is a bug
note: try running with RUST_LOG=rustc=1 to get further details and report the results to github.com/mozilla/rust/issues
task <unnamed> failed at 'explicit failure', /home/simon/projects/servo/src/compiler/rust/src/librustc/rustc.rs:376
make: *** [servo] Erreur 101

Is there more information that I can provide to help with this?

[pcwalton]

I can look into this today. Do you have instructions for reproducing?

[SimonSapin]

Not really. I was in the middle of upgrading Rust in Servo, and make clean (rather than just make clean-fast) fixed this issue for me. Closing for now.