Internal compiler error, borrow checker?

[nwin]

I would like to give a nice minimal example this time but I have no idea which part of my code triggers this bug, it's a result of an internal api change which resulted in a lot of changes… :-(

$ RUST_BACKTRACE=1 rustc src/lib.rs 
error: internal compiler error: unexpected failure
note: the compiler hit an unexpected failure path. 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
task 'rustc' failed at 'assertion failed: self.nodeid_to_index.contains_key(&id)', /Users/rustbuild/src/rust-buildbot/slave/nightly-mac/build/src/librustc/middle/dataflow.rs:286

stack backtrace:
   1:        0x11135dc18 - rt::backtrace::imp::write::h43147c4def9aa280Ffq
   2:        0x111361405 - failure::on_fail::h9c97bab6285818b6Yvq
   3:        0x1116141f9 - unwind::begin_unwind_inner::h9953e3233f8e8e31AXd
   4:        0x111613d87 - unwind::begin_unwind_fmt::h0aaa009accf3c8603Ud
   5:        0x10e6cc429 - middle::borrowck::build_borrowck_dataflow_data::hf038e5d9ffd145aevxP
   6:        0x10e6c8063 - middle::borrowck::borrowck_fn::h09c99839aac7c519ruP
   7:        0x10e6cb153 - visit::walk_method_helper::h15279296949109789107
   8:        0x10e6c8f35 - middle::borrowck::borrowck_item::h6998b8876678d119ytP
   9:        0x10e6c8f71 - middle::borrowck::borrowck_item::h6998b8876678d119ytP
  10:        0x10e6c91c1 - middle::borrowck::check_crate::hd53fa5b789f8aaadwmP
  11:        0x10e9d6233 - driver::driver::phase_3_run_analysis_passes::hca92301df3914a90dPt
  12:        0x10e9d0de1 - driver::driver::compile_input::h2a63d2105a548c23eBt
  13:        0x10ea84ab8 - driver::run_compiler::ha7f89b05ee9a4f7diIw
  14:        0x10ea82186 - driver::main_args::closure.$x22closure$x22$LP$134556$RP$
  15:        0x10ea9530b - task::TaskBuilder<S>::try_future::closure.$x22closure$x22$LP$135705$RP$
  16:        0x10ea95201 - task::TaskBuilder<S>::spawn_internal::closure.$x22closure$x22$LP$135682$RP$
  17:        0x11128963c - task::spawn_opts::closure.$x22closure$x22$LP$8270$RP$
  18:        0x11167936c - rust_try
  19:        0x111610f5b - unwind::try::h6c145dd9c626c3b6ZLd
  20:        0x111610cc3 - task::Task::run::h733761579f62e5f8RXc
  21:        0x1112894d1 - task::spawn_opts::closure.$x22closure$x22$LP$8215$RP$
  22:        0x111612f56 - thread::thread_start::h51c3f68f0794f335pkd
  23:     0x7fff82b49899 - _pthread_body
  24:     0x7fff82b4972a - _pthread_struct_init

[nwin]

Ok, I finally managed it.

pub fn foo(params: Option<&[&str]>) {}

fn main() {
    let name = "Foo";
    let msg = foo(Some(&[name.as_slice()]));
}

Seems fine now but potentially needs a test.