<p dir="auto">$ rustc --version<br>
rustc 1.2.0 (<a class="commit-link" data-hovercard-type="commit" data-hovercard-url="https://github.com/rust-lang/rust/commit/082e4763615bdbe7b4dd3dfd6fc2210b7773edf5/hovercard" href="https://github.com/rust-lang/rust/commit/082e4763615bdbe7b4dd3dfd6fc2210b7773edf5"><tt>082e476</tt></a> 2015-08-03)</p>
<p dir="auto">$ RUST_BACKTRACE=1 cargo build<br>
error: internal compiler error: unexpected panic<br>
note: the compiler unexpectedly panicked. this is a bug.<br>
note: we would appreciate a bug report: <a href="https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports">https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports</a><br>
thread 'rustc' panicked at 'assertion failed: index.end &lt;= self.len()', ../src/libcore/slice.rs:544</p>
<p dir="auto">stack backtrace:<br>
1:        0x1058dd7b5 - sys::backtrace::write::hf5ea20500b66cd24uns<br>
2:        0x1058e6013 - panicking::on_panic::hbe02cb0d925cad49iGw<br>
3:        0x1058a1dd2 - rt::unwind::begin_unwind_inner::h12ba0ba9dffdecc2uow<br>
4:        0x1058a2b29 - rt::unwind::begin_unwind_fmt::hadf0dbf11d345ebfAnw<br>
5:        0x1058e5b9c - rust_begin_unwind<br>
6:        0x105939d95 - panicking::panic_fmt::h987a4890059dc6e0H8B<br>
7:        0x1059327e1 - panicking::panic::hfd3e1c225039d9cae7B<br>
8:        0x1029106ae - astconv::finish_resolving_def_to_ty::he5ea7cd41915b99d76v<br>
9:        0x1028cee6b - astconv::ast_ty_to_ty::hf914e7106582dfb2V8v<br>
10:        0x10291bf9f - astconv::ast_ty_arg_to_ty::hd7f3449b6ed7d80f3Zv<br>
11:        0x10291bc4a - vec::Vec.FromIterator::from_iter::h14554187055721803077<br>
12:        0x102919bb7 - astconv::convert_angle_bracketed_parameters::h1f04abd7bdcd3d52H2u<br>
13:        0x1028cc5aa - astconv::ast_path_substs_for_ty::h0a1cd0aaeb5403f5lLu<br>
14:        0x102920de5 - astconv::ast_path_to_ty::h8c49a0891a1ce609Brv<br>
15:        0x10290e149 - astconv::finish_resolving_def_to_ty::he5ea7cd41915b99d76v<br>
16:        0x1028cee6b - astconv::ast_ty_to_ty::hf914e7106582dfb2V8v<br>
17:        0x10291ce02 - astconv::convert_ty_with_lifetime_elision::h4459fb498cc71b5756u<br>
18:        0x102925bfd - astconv::ty_of_method_or_bare_fn::haa63c3b9895211a0Now<br>
19:        0x1029412b9 - collect::convert_method::h80cba98fe26dd14afLx<br>
20:        0x10292f9b6 - collect::convert_item::h2cca9c39f6b8d796R0x<br>
21:        0x102928706 - collect::collect_item_types::hf0bc00065ee6508bW7w<br>
22:        0x10297948a - check_crate::h117ec0c1269afe619fD<br>
23:        0x1021bad16 - driver::phase_3_run_analysis_passes::closure.15766<br>
24:        0x1021b9204 - middle::ty::with_ctxt::h14728011725879770170<br>
25:        0x1021b400a - driver::phase_3_run_analysis_passes::h16713467199444562124<br>
26:        0x102197107 - driver::compile_input::hb6d2be5b0fa2247fTba<br>
27:        0x10227313f - run_compiler::h21d74b88eec3fe3bx7b<br>
28:        0x1022709f3 - boxed::F.FnBox::call_box::h1689969825914258414<br>
29:        0x1022701b7 - rt::unwind::try::try_fn::h11273853850686318048<br>
30:        0x105970cc8 - rust_try_inner<br>
31:        0x105970cb5 - rust_try<br>
32:        0x1058cfc95 - rt::unwind::try::inner_try::h480e3107f6a4b5b9nkw<br>
33:        0x1022703e8 - boxed::F.FnBox::call_box::h888215220722514405<br>
34:        0x1058e4a9d - sys:<g-emoji class="g-emoji" alias="thread" fallback-src="https://github.githubassets.com/images/icons/emoji/unicode/1f9f5.png">🧵</g-emoji>:Thread:<g-emoji class="g-emoji" alias="new" fallback-src="https://github.githubassets.com/images/icons/emoji/unicode/1f195.png">🆕</g-emoji>:thread_start::hdb3d925f69c5da4aHIv<br>
35:     0x7fff9916d267 - _pthread_body<br>
36:     0x7fff9916d1e4 - _pthread_start</p>
<p dir="auto">Any guidance on finding the code which is tickling this would be appreciated as I am dead in the water.</p>
<p dir="auto">Thanks.</p>
<p dir="auto">with rustc 1.0.0-nightly (<a class="commit-link" data-hovercard-type="commit" data-hovercard-url="https://github.com/rust-lang/rust/commit/157614249594f187f421cd97f928e64c5ab5c1fa/hovercard" href="https://github.com/rust-lang/rust/commit/157614249594f187f421cd97f928e64c5ab5c1fa"><tt>1576142</tt></a> 2015-03-01) (built 2015-03-01)</p>
<div class="highlight highlight-source-rust notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="use std::iter::IntoIterator::IntoIter;
fn main()
{
    let mul2 = |x:IntoIter| x.iter().map(|x| x);
}"><pre class="notranslate"><span class="pl-k">use</span> std<span class="pl-kos">::</span>iter<span class="pl-kos">::</span><span class="pl-smi">IntoIterator</span><span class="pl-kos">::</span><span class="pl-v">IntoIter</span><span class="pl-kos">;</span>
<span class="pl-k">fn</span> <span class="pl-en">main</span><span class="pl-kos">(</span><span class="pl-kos">)</span>
<span class="pl-kos">{</span>
    <span class="pl-k">let</span> mul2 = |<span class="pl-s1">x</span><span class="pl-kos">:</span><span class="pl-smi">IntoIter</span>| x<span class="pl-kos">.</span><span class="pl-en">iter</span><span class="pl-kos">(</span><span class="pl-kos">)</span><span class="pl-kos">.</span><span class="pl-en">map</span><span class="pl-kos">(</span>|x| x<span class="pl-kos">)</span><span class="pl-kos">;</span>
<span class="pl-kos">}</span></pre></div>