Internal Compiler Error: unexpected failure

[bsummer4]

I get the following error,

$ RUST_LOG=rustc=1 rustc bug.rs
task 'rustc' failed at 'called `Option::unwrap()` on a `None` value', ~/hack/rust/src/libstd/option.rs:133
error: internal compiler error: unexpected failure
This message reflects a bug in the Rust compiler. 
We would appreciate a bug report: https://github.com/mozilla/rust/wiki/HOWTO-submit-a-Rust-bug-report
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 '<main>' failed at 'explicit failure', ~/hack/rust/src/librustc/lib.rs:440

on the following code:

$ cat bug.rs
fn main () {
  let x : Option<~[~str]> = match ~[&"A"] {
    [] => { None }
    [&"A",..a] => { Some(~[]) }
    [&"B",..b] => { Some(~[]) }}; }

Running on:

$ rustc -v
rustc 0.9-pre (a1d3cc5 2013-12-30 18:56:54 -0800)
host: i686-unknown-linux-gnu

[sfackler]

Here's a backtrace:

Breakpoint 1, 0x00007fff892abf68 in _Unwind_Resume ()
(gdb) bt
#0  0x00007fff892abf68 in _Unwind_Resume ()
#1  0x000000010000651c in rt::unwind::Unwinder::begin_unwind::h39752c91d9912e9579ab::v0.9.pre ()
#2  0x0000000100fd5067 in rt::unwind::begin_unwind::h1ec8aebf2376f51faG::v0.9.pre ()
#3  0x000000010137cf9b in middle::check_match::is_useful_specialized::hc31b86ea871e8226as::v0.9.pre ()
#4  0x000000010137a3db in middle::check_match::is_useful::h983772b255163d0baf::v0.9.pre ()
#5  0x0000000101370e96 in middle::check_match::Visitor$CheckMatchVisitor::visit_expr::h7e76736f097b5f55LuaG::v0.9.pre ()
#6  0x0000000101382a89 in visit::walk_local::hd70877e119883467aa::v0.9.pre ()
#7  0x00000001013724a3 in middle::check_match::Visitor$CheckMatchVisitor::visit_local::h3882c05f908d93f5LuaK::v0.9.pre ()
#8  0x00000001013767c3 in visit::walk_stmt::h3bd7297ea40443caaK::v0.9.pre ()
#9  0x00000001013765f8 in visit::walk_block::hd041e1ac11200266aI::v0.9.pre ()
#10 0x000000010138334a in visit::walk_fn::h796eb05c19838cb1ac::v0.9.pre ()
#11 0x00000001013727fa in middle::check_match::Visitor$CheckMatchVisitor::visit_fn::h8867671beaf2e9d4LuaR::v0.9.pre ()
#12 0x0000000101373a40 in visit::walk_item::h9867cb73d22bc5bcac::v0.9.pre ()
#13 0x0000000101372f26 in visit::walk_mod::hb8e0c4e9c1f01b10aX::v0.9.pre ()
#14 0x0000000101372ae7 in middle::check_match::check_crate::hc5908ffd3ed04a0aaH::v0.9.pre ()
#15 0x000000010136adff in util::common::time::hcdbea6e7d86ce6f7aO::v0.9.pre ()
#16 0x000000010164b700 in driver::driver::phase_3_run_analysis_passes::h1288dcb8cc9adc5eam::v0.9.pre ()
#17 0x000000010165095d in driver::driver::compile_input::h930603a3541153d8aK::v0.9.pre ()
#18 0x0000000101673a09 in run_compiler::hbfa8b0fe92856741aA::v0.9.pre ()
#19 0x00000001016820ad in main_args::anon::expr_fn::ae ()
#20 0x0000000101680174 in monitor::anon::expr_fn::ao ()
#21 0x000000010167924e in task::TaskBuilder::try::anon::expr_fn::sEacaQ ()
#22 0x00000001005cca98 in task::__extensions__::build_start_wrapper::anon::anon::expr_fn::aQ ()
#23 0x00000001000a46e8 in rt::task::__extensions__::run::anon::expr_fn::aF ()
#24 0x00000001000ab51c in rust_try ()
#25 0x00000001005cc4bc in task::__extensions__::build_start_wrapper::anon::expr_fn::az ()

[Armavica]

I will give a shot at debugging this.

[alexcrichton]

Closing, matching over ~[T] has been removed.