<p dir="auto">I was doing some refactoring on <a href="https://github.com/RoxasShadow/rust-cleverbot">rust-cleverbot</a> and then I encountered the error below. The following one is the diff of the changes I applied in order to get it: <a href="https://github.com/RoxasShadow/rust-cleverbot/compare/onoez?expand=1">https://github.com/RoxasShadow/rust-cleverbot/compare/onoez?expand=1</a></p>
<h2 dir="auto">Meta</h2>
<p dir="auto"><code class="notranslate">rustc --version --verbose</code>:</p>
<blockquote>
<p dir="auto">rustc 1.0.0 (<a class="commit-link" data-hovercard-type="commit" data-hovercard-url="https://github.com/rust-lang/rust/commit/a59de37e99060162a2674e3ff45409ac73595c0e/hovercard" href="https://github.com/rust-lang/rust/commit/a59de37e99060162a2674e3ff45409ac73595c0e"><tt>a59de37</tt></a> 2015-05-13) (built 2015-05-14)<br>
binary: rustc<br>
commit-hash: <a class="commit-link" data-hovercard-type="commit" data-hovercard-url="https://github.com/rust-lang/rust/commit/a59de37e99060162a2674e3ff45409ac73595c0e/hovercard" href="https://github.com/rust-lang/rust/commit/a59de37e99060162a2674e3ff45409ac73595c0e"><tt>a59de37</tt></a><br>
commit-date: 2015-05-13<br>
build-date: 2015-05-14<br>
host: x86_64-apple-darwin<br>
release: 1.0.0</p>
</blockquote>
<p dir="auto">Backtrace:</p>
<blockquote>
<p dir="auto">┌[giovanni@Mozes-Air] [/dev/ttys001] [onoez]<br>
└[~/Desktop/rust-cleverbot]&gt; cargo run --example think Ciao! --verbose<br>
Fresh libc v0.1.8<br>
Fresh unicase v0.1.0<br>
Fresh httparse v0.1.2<br>
Fresh bitflags v0.1.1<br>
Fresh lazy_static v0.1.10<br>
Fresh matches v0.1.2<br>
Fresh typeable v0.1.1<br>
Fresh rustc-serialize v0.3.14<br>
Fresh traitobject v0.0.1<br>
Fresh gcc v0.3.5<br>
Fresh pkg-config v0.3.4<br>
Fresh rand v0.3.8<br>
Fresh log v0.3.1<br>
Fresh num_cpus v0.2.6<br>
Fresh url v0.2.34<br>
Fresh mime v0.0.11<br>
Fresh time v0.1.25<br>
Fresh openssl-sys v0.6.2<br>
Fresh rust-crypto v0.2.31<br>
Fresh openssl v0.6.2<br>
Compiling rust-cleverbot v0.0.1 (file:///Users/giovanni/Desktop/rust-cleverbot)<br>
Running <code class="notranslate">rustc src/lib.rs --crate-name cleverbot --crate-type lib -g --out-dir /Users/giovanni/Desktop/rust-cleverbot/target/debug --emit=dep-info,link -L dependency=/Users/giovanni/Desktop/rust-cleverbot/target/debug -L dependency=/Users/giovanni/Desktop/rust-cleverbot/target/debug/deps --extern url=/Users/giovanni/Desktop/rust-cleverbot/target/debug/deps/liburl-beb2c5952735425a.rlib --extern crypto=/Users/giovanni/Desktop/rust-cleverbot/target/debug/deps/libcrypto-67f1ad94f3ffe5f4.rlib --extern hyper=/Users/giovanni/Desktop/rust-cleverbot/target/debug/deps/libhyper-f7b4259bc2dab307.rlib -L native=/usr/lib -L native=/Users/giovanni/Desktop/rust-cleverbot/target/debug/build/openssl-sys-5040130ff99796a0/out -L native=/Users/giovanni/Desktop/rust-cleverbot/target/debug/build/rust-crypto-67f1ad94f3ffe5f4/out -L native=/Users/giovanni/Desktop/rust-cleverbot/target/debug/build/time-e758cbe877e9589d/out</code><br>
Fresh cookie v0.1.20<br>
Fresh hyper v0.5.1<br>
src/lib.rs:1:1: 1:1 error: internal compiler error: cannot relate bound region: ReStatic &lt;= ReEarlyBound(360, TypeSpace, 0, 'a)<br>
src/lib.rs:1 extern crate url;<br>
^<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>
note: run with <code class="notranslate">RUST_BACKTRACE=1</code> for a backtrace<br>
thread 'rustc' panicked at 'Box', /Users/rustbuild/src/rust-buildbot/slave/stable-dist-rustc-mac/build/src/libsyntax/diagnostic.rs:149<br>
stack backtrace:<br>
1:        0x103a45e7f - sys::backtrace::write::h7807ec07859fb503t1r<br>
2:        0x103a4e4b2 - panicking::on_panic::ha0ed2b9b562a7f9ctZv<br>
3:        0x103a0ae35 - rt::unwind::begin_unwind_inner::hbfb8d99cb52be7a1cHv<br>
4:        0x1031e743e - rt::unwind::begin_unwind::h14482673826369992638<br>
5:        0x1031e73ca - diagnostic::SpanHandler::span_bug::ha80d5103c6dc346fEqB<br>
6:        0x1010acc2b - middle::infer::region_inference::RegionVarBindings&lt;'a, 'tcx&gt;::make_subregion::h424c309cfde0bc8dtiv<br>
7:        0x101063c9b - middle::infer::sub::Sub&lt;'a, 'tcx&gt;.TypeRelation&lt;'a, 'tcx&gt;::regions::h7b6335e10c5e2accAux<br>
8:        0x101063a81 - middle::infer::sub::Sub&lt;'a, 'tcx&gt;.TypeRelation&lt;'a, 'tcx&gt;::relate_with_variance::h14347860495291865360<br>
9:        0x101062ffb - middle::ty_relate::relate_substs::h12261092315780768762<br>
10:        0x1010625ea - middle::ty_relate::relate_item_substs::h10479042000615633136<br>
11:        0x1010c3724 - middle::ty_relate::super_relate_tys::h8062529144464697345<br>
12:        0x10105aea2 - middle::infer::sub::Sub&lt;'a, 'tcx&gt;.TypeRelation&lt;'a, 'tcx&gt;::tys::h39efa003c9af43d1dqx<br>
13:        0x1010c8227 - middle::infer::InferCtxt&lt;'a, 'tcx&gt;::sub_types::h43541a86e23825d8Xjz<br>
14:        0x1006eee35 - check::method::probe::ProbeContext&lt;'a, 'tcx&gt;::consider_candidates::hb77291381a7d8dc300h<br>
15:        0x1006eebd9 - check::method::probe::ProbeContext&lt;'a, 'tcx&gt;::pick_method::ha530aac6fb2586e2XWh<br>
16:        0x1006edfa6 - check::method::probe::ProbeContext&lt;'a, 'tcx&gt;::pick_core::h9d29a0dbf0c8dd7bRRh<br>
17:        0x1006e378c - check::method::probe::probe::closure.31169<br>
18:        0x1006e0e59 - check::method::probe::probe::hc6eba1678c1d154fWGg<br>
19:        0x1006fbb7d - check::method::resolve_ufcs::he4f736b36751a4a2gJj<br>
20:        0x100788280 - check::check_expr_with_unifier::h3772037143783809604<br>
21:        0x10071d25c - check::callee::check_call::h6e64f97ca920f598QTl<br>
22:        0x10076bd51 - check::check_expr_with_unifier::h11298596628612541945<br>
23:        0x100792a7b - check::check_decl_local::hf2bb5e27a41be699hOr<br>
24:        0x10073b1da - check::check_block_with_expected::h1a2a965f24479edbnUr<br>
25:        0x10071c828 - check::check_fn::h4b472c723dc36ca2UGn<br>
26:        0x100736985 - check::check_bare_fn::h87d6505bed3e4c61twn<br>
27:        0x10073f887 - check::check_method_body::h1802c6d6e15675a6Y7n<br>
28:        0x1007348cb - check::CheckItemBodiesVisitor&lt;'a, 'tcx&gt;.Visitor&lt;'tcx&gt;::visit_item::h97ae569543a98538wtn<br>
29:        0x1007fef4a - check_crate::closure.38028<br>
30:        0x1007fa357 - check_crate::h722813c75c795e06XcC<br>
31:        0x1005635f4 - driver::phase_3_run_analysis_passes::h3394cefeecbff846nGa<br>
32:        0x100544ffc - driver::compile_input::hf0607b3d1fd498bcQba<br>
33:        0x10060d5a3 - run_compiler::he7a5311c755081d7z4b<br>
34:        0x10060b0ca - boxed::F.FnBox::call_box::h5234503372052129763<br>
35:        0x10060a567 - rt::unwind::try::try_fn::h4031265711883657142<br>
36:        0x103acf508 - rust_try_inner<br>
37:        0x103acf4f5 - rust_try<br>
38:        0x10060a840 - boxed::F.FnBox::call_box::h1044299548107784679<br>
39:        0x103a4cffd - sys:<g-emoji class="g-emoji" alias="thread" fallback-src="https://github.githubassets.com/images/icons/emoji/unicode/1f9f5.png">🧵</g-emoji>:create::thread_start::ha3be9b31a8775143L4u<br>
40:     0x7fff916a4267 - _pthread_body<br>
41:     0x7fff916a41e4 - _pthread_start<br>
Could not compile <code class="notranslate">rust-cleverbot</code>.<br>
Caused by:<br>
Process didn't exit successfully: <code class="notranslate">rustc src/lib.rs --crate-name cleverbot --crate-type lib -g --out-dir /Users/giovanni/Desktop/rust-cleverbot/target/debug --emit=dep-info,link -L dependency=/Users/giovanni/Desktop/rust-cleverbot/target/debug -L dependency=/Users/giovanni/Desktop/rust-cleverbot/target/debug/deps --extern url=/Users/giovanni/Desktop/rust-cleverbot/target/debug/deps/liburl-beb2c5952735425a.rlib --extern crypto=/Users/giovanni/Desktop/rust-cleverbot/target/debug/deps/libcrypto-67f1ad94f3ffe5f4.rlib --extern hyper=/Users/giovanni/Desktop/rust-cleverbot/target/debug/deps/libhyper-f7b4259bc2dab307.rlib -L native=/usr/lib -L native=/Users/giovanni/Desktop/rust-cleverbot/target/debug/build/openssl-sys-5040130ff99796a0/out -L native=/Users/giovanni/Desktop/rust-cleverbot/target/debug/build/rust-crypto-67f1ad94f3ffe5f4/out -L native=/Users/giovanni/Desktop/rust-cleverbot/target/debug/build/time-e758cbe877e9589d/out</code> (exit code: 101)</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content=""><pre class="notranslate"><code class="notranslate"></code></pre></div>
</blockquote>
<p dir="auto">I've encountered an internal compiler error when building this code:</p>
<div class="highlight highlight-source-rust notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="use std::iter::*;

pub struct Ilbm&lt;'a&gt; {
    body_data: &amp;'a[u8],
    data_width: u16,
    depth: u8,
    mask: u8,
    ham: bool,
}

impl&lt;'a&gt; Ilbm&lt;'a&gt; {

    fn get_bit(buffer: &amp;[u8], col: usize) -&gt; u8 {
        let byte_offset = col / 8;
        let bit_offset = 7 - col % 8;
        let byte_val = buffer[byte_offset];
        (byte_val &gt;&gt; bit_offset) &amp; 1
    }

    fn draw_row&lt;'b&gt;(&amp;self, decoded_row_planes: Vec&lt;&amp;'b [u8]&gt;) -&gt; Box&lt;Iterator&lt;Item=u8&gt; + 'b&gt; {
        let masking = self.mask == 1;

        let ham_mask: u8 = if self.ham { if self.depth == 6 { 0x0F } else { 0x3F } } else { 0 };
        let ham_shif: u8 = if self.ham { self.depth - 2 } else { 0 };
        let depth = self.depth as usize;

        Box::new((0..self.data_width)
                 .flat_map(move |col| {
                     if masking &amp;&amp; Self::get_bit(decoded_row_planes[depth], col as usize) != 1 {
                         repeat(0).take(4)
                     }
                     else {
                        decoded_row_planes[depth][col as usize]
                     }
                 } ))
    }

}"><pre class="notranslate"><span class="pl-k">use</span> std<span class="pl-kos">::</span>iter<span class="pl-kos">::</span><span class="pl-c1">*</span><span class="pl-kos">;</span>

<span class="pl-k">pub</span> <span class="pl-k">struct</span> <span class="pl-smi">Ilbm</span><span class="pl-kos">&lt;</span><span class="pl-c1">'</span><span class="pl-ent">a</span><span class="pl-kos">&gt;</span> <span class="pl-kos">{</span>
    <span class="pl-c1">body_data</span><span class="pl-kos">:</span> <span class="pl-c1">&amp;</span><span class="pl-c1">'</span><span class="pl-ent">a</span><span class="pl-kos">[</span><span class="pl-smi">u8</span><span class="pl-kos">]</span><span class="pl-kos">,</span>
    <span class="pl-c1">data_width</span><span class="pl-kos">:</span> <span class="pl-smi">u16</span><span class="pl-kos">,</span>
    <span class="pl-c1">depth</span><span class="pl-kos">:</span> <span class="pl-smi">u8</span><span class="pl-kos">,</span>
    <span class="pl-c1">mask</span><span class="pl-kos">:</span> <span class="pl-smi">u8</span><span class="pl-kos">,</span>
    <span class="pl-c1">ham</span><span class="pl-kos">:</span> <span class="pl-smi">bool</span><span class="pl-kos">,</span>
<span class="pl-kos">}</span>

<span class="pl-k">impl</span><span class="pl-kos">&lt;</span><span class="pl-c1">'</span><span class="pl-ent">a</span><span class="pl-kos">&gt;</span> <span class="pl-smi">Ilbm</span><span class="pl-kos">&lt;</span><span class="pl-c1">'</span><span class="pl-ent">a</span><span class="pl-kos">&gt;</span> <span class="pl-kos">{</span>

    <span class="pl-k">fn</span> <span class="pl-en">get_bit</span><span class="pl-kos">(</span><span class="pl-s1">buffer</span><span class="pl-kos">:</span> <span class="pl-c1">&amp;</span><span class="pl-kos">[</span><span class="pl-smi">u8</span><span class="pl-kos">]</span><span class="pl-kos">,</span> <span class="pl-s1">col</span><span class="pl-kos">:</span> <span class="pl-smi">usize</span><span class="pl-kos">)</span> -&gt; <span class="pl-smi">u8</span> <span class="pl-kos">{</span>
        <span class="pl-k">let</span> byte_offset = col / <span class="pl-c1">8</span><span class="pl-kos">;</span>
        <span class="pl-k">let</span> bit_offset = <span class="pl-c1">7</span> - col % <span class="pl-c1">8</span><span class="pl-kos">;</span>
        <span class="pl-k">let</span> byte_val = buffer<span class="pl-kos">[</span>byte_offset<span class="pl-kos">]</span><span class="pl-kos">;</span>
        <span class="pl-kos">(</span>byte_val &gt;&gt; bit_offset<span class="pl-kos">)</span> <span class="pl-c1">&amp;</span> <span class="pl-c1">1</span>
    <span class="pl-kos">}</span>

    <span class="pl-k">fn</span> <span class="pl-en">draw_row</span><span class="pl-kos">&lt;</span><span class="pl-c1">'</span><span class="pl-ent">b</span><span class="pl-kos">&gt;</span><span class="pl-kos">(</span><span class="pl-c1">&amp;</span><span class="pl-smi">self</span><span class="pl-kos">,</span> <span class="pl-s1">decoded_row_planes</span><span class="pl-kos">:</span> <span class="pl-smi">Vec</span><span class="pl-kos">&lt;</span><span class="pl-c1">&amp;</span><span class="pl-c1">'</span><span class="pl-ent">b</span> <span class="pl-kos">[</span><span class="pl-smi">u8</span><span class="pl-kos">]</span><span class="pl-kos">&gt;</span><span class="pl-kos">)</span> -&gt; <span class="pl-smi">Box</span><span class="pl-kos">&lt;</span><span class="pl-smi">Iterator</span><span class="pl-kos">&lt;</span><span class="pl-smi">Item</span>=<span class="pl-smi">u8</span><span class="pl-kos">&gt;</span> + <span class="pl-c1">'</span><span class="pl-ent">b</span><span class="pl-kos">&gt;</span> <span class="pl-kos">{</span>
        <span class="pl-k">let</span> masking = <span class="pl-smi">self</span><span class="pl-kos">.</span><span class="pl-c1">mask</span> == <span class="pl-c1">1</span><span class="pl-kos">;</span>

        <span class="pl-k">let</span> ham_mask<span class="pl-kos">:</span> <span class="pl-smi">u8</span> = <span class="pl-k">if</span> <span class="pl-smi">self</span><span class="pl-kos">.</span><span class="pl-c1">ham</span> <span class="pl-kos">{</span> <span class="pl-k">if</span> <span class="pl-smi">self</span><span class="pl-kos">.</span><span class="pl-c1">depth</span> == <span class="pl-c1">6</span> <span class="pl-kos">{</span> <span class="pl-c1">0x0F</span> <span class="pl-kos">}</span> <span class="pl-k">else</span> <span class="pl-kos">{</span> <span class="pl-c1">0x3F</span> <span class="pl-kos">}</span> <span class="pl-kos">}</span> <span class="pl-k">else</span> <span class="pl-kos">{</span> <span class="pl-c1">0</span> <span class="pl-kos">}</span><span class="pl-kos">;</span>
        <span class="pl-k">let</span> ham_shif<span class="pl-kos">:</span> <span class="pl-smi">u8</span> = <span class="pl-k">if</span> <span class="pl-smi">self</span><span class="pl-kos">.</span><span class="pl-c1">ham</span> <span class="pl-kos">{</span> <span class="pl-smi">self</span><span class="pl-kos">.</span><span class="pl-c1">depth</span> - <span class="pl-c1">2</span> <span class="pl-kos">}</span> <span class="pl-k">else</span> <span class="pl-kos">{</span> <span class="pl-c1">0</span> <span class="pl-kos">}</span><span class="pl-kos">;</span>
        <span class="pl-k">let</span> depth = <span class="pl-smi">self</span><span class="pl-kos">.</span><span class="pl-c1">depth</span> <span class="pl-k">as</span> <span class="pl-smi">usize</span><span class="pl-kos">;</span>

        <span class="pl-smi">Box</span><span class="pl-kos">::</span><span class="pl-en">new</span><span class="pl-kos">(</span><span class="pl-kos">(</span><span class="pl-c1">0</span>..<span class="pl-smi">self</span><span class="pl-kos">.</span><span class="pl-c1">data_width</span><span class="pl-kos">)</span>
                 <span class="pl-kos">.</span><span class="pl-en">flat_map</span><span class="pl-kos">(</span><span class="pl-k">move</span> |col| <span class="pl-kos">{</span>
                     <span class="pl-k">if</span> masking &amp;&amp; <span class="pl-smi">Self</span><span class="pl-kos">::</span><span class="pl-en">get_bit</span><span class="pl-kos">(</span>decoded_row_planes<span class="pl-kos">[</span>depth<span class="pl-kos">]</span><span class="pl-kos">,</span> col <span class="pl-k">as</span> <span class="pl-smi">usize</span><span class="pl-kos">)</span> != <span class="pl-c1">1</span> <span class="pl-kos">{</span>
                         <span class="pl-en">repeat</span><span class="pl-kos">(</span><span class="pl-c1">0</span><span class="pl-kos">)</span><span class="pl-kos">.</span><span class="pl-en">take</span><span class="pl-kos">(</span><span class="pl-c1">4</span><span class="pl-kos">)</span>
                     <span class="pl-kos">}</span>
                     <span class="pl-k">else</span> <span class="pl-kos">{</span>
                        decoded_row_planes<span class="pl-kos">[</span>depth<span class="pl-kos">]</span><span class="pl-kos">[</span>col <span class="pl-k">as</span> <span class="pl-smi">usize</span><span class="pl-kos">]</span>
                     <span class="pl-kos">}</span>
                 <span class="pl-kos">}</span> <span class="pl-kos">)</span><span class="pl-kos">)</span>
    <span class="pl-kos">}</span>

<span class="pl-kos">}</span></pre></div>
<h2 dir="auto">Meta</h2>
<p dir="auto"><code class="notranslate">rustc --version --verbose</code>:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="rustc 1.0.0-beta.3 (5241bf9c3 2015-04-25) (built 2015-04-25)
binary: rustc
commit-hash: 5241bf9c34d156ea6064367a33cbd7222eeb5789
commit-date: 2015-04-25
build-date: 2015-04-25
host: x86_64-apple-darwin
release: 1.0.0-beta.3"><pre class="notranslate"><code class="notranslate">rustc 1.0.0-beta.3 (5241bf9c3 2015-04-25) (built 2015-04-25)
binary: rustc
commit-hash: 5241bf9c34d156ea6064367a33cbd7222eeb5789
commit-date: 2015-04-25
build-date: 2015-04-25
host: x86_64-apple-darwin
release: 1.0.0-beta.3
</code></pre></div>
<p dir="auto">Backtrace:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="thread 'rustc' panicked at 'Box&lt;Any&gt;', /Users/rustbuild/src/rust-buildbot/slave/beta-dist-rustc-mac/build/src/libsyntax/diagnostic.rs:149

stack backtrace:
   1:        0x10affc33f - sys::backtrace::write::h0f2fc53eb11eb814gWr
   2:        0x10b004942 - panicking::on_panic::hd617a4042e8486fciUv
   3:        0x10afc1375 - rt::unwind::begin_unwind_inner::hd84dfec22ac3667d1Bv
   4:        0x10a7a09fe - rt::unwind::begin_unwind::h17792509132866387090
   5:        0x10a7a098a - diagnostic::SpanHandler::span_bug::hebb6215f61f436aaEqB
   6:        0x10867405b - middle::infer::region_inference::RegionVarBindings&lt;'a, 'tcx&gt;::make_subregion::h4adb78ad460601ecS8u
   7:        0x10862aeab - middle::infer::sub::Sub&lt;'a, 'tcx&gt;.TypeRelation&lt;'a, 'tcx&gt;::regions::h3f9ee82a2e72a144Mjx
   8:        0x10862ac91 - middle::infer::sub::Sub&lt;'a, 'tcx&gt;.TypeRelation&lt;'a, 'tcx&gt;::relate_with_variance::h5672739467683317342
   9:        0x10862a20b - middle::ty_relate::relate_substs::h2389761154872115822
  10:        0x1086297fa - middle::ty_relate::relate_item_substs::h7360249961707336134
  11:        0x10868b447 - middle::ty_relate::super_relate_tys::h10795509169925483940
  12:        0x108621bb2 - middle::infer::sub::Sub&lt;'a, 'tcx&gt;.TypeRelation&lt;'a, 'tcx&gt;::tys::h3174a850422a5fc1pfx
  13:        0x10868ff47 - middle::infer::InferCtxt&lt;'a, 'tcx&gt;::sub_types::hea49ed0ad06eecf898y
  14:        0x107ccd1d5 - check::method::probe::ProbeContext&lt;'a, 'tcx&gt;::consider_candidates::h2b54d2790fd0880dXoi
  15:        0x107cccf79 - check::method::probe::ProbeContext&lt;'a, 'tcx&gt;::pick_method::hc768ec9b0fb6e87dUki
  16:        0x107ccc346 - check::method::probe::ProbeContext&lt;'a, 'tcx&gt;::pick_core::h3e5895ad5629b90bOfi
  17:        0x107cc1cbc - check::method::probe::probe::closure.31574
  18:        0x107cbf389 - check::method::probe::probe::hfbf147788d37ee49T4g
  19:        0x107cd9ecd - check::method::resolve_ufcs::h9a77d5ebe946bd48d7j
  20:        0x107d65c30 - check::check_expr_with_unifier::h1091590169474595220
  21:        0x107cfaf2c - check::callee::check_call::hf304e98e66e2eee3Nhm
  22:        0x107d61b0a - check::check_expr_with_unifier::h1091590169474595220
  23:        0x107d0a18d - check::op::check_binop::h6504e0630336d4baFan
  24:        0x107d498ae - check::check_expr_with_unifier::h4364205555285070129
  25:        0x107d0a42e - check::op::check_binop::h6504e0630336d4baFan
  26:        0x107d4343b - check::check_expr_with_unifier::h8963715346170232283
  27:        0x107d2f66d - check::check_expr_with_unifier::check_then_else::h1d5d0ab6867397defIq
  28:        0x107d49b8d - check::check_expr_with_unifier::h4364205555285070129
  29:        0x107d191db - check::check_block_with_expected::h83c5e18f3456d9895hs
  30:        0x107d49d85 - check::check_expr_with_unifier::h4364205555285070129
  31:        0x107d191db - check::check_block_with_expected::h83c5e18f3456d9895hs
  32:        0x107cfa508 - check::check_fn::h5c814037ea8a2362C4n
  33:        0x107cf8966 - check::closure::check_expr_closure::h0b5d1648c0a7d5409Pl
  34:        0x107d25f08 - check::check_expr_with_unifier::h8674341778859500334
  35:        0x107d00d9c - check::check_argument_types::hbd54866e0651a010O5p
  36:        0x107d0208a - check::check_method_argument_types::h42f31152b61f4a11d3p
  37:        0x107d308cc - check::check_expr_with_unifier::check_method_call::h6fc40daeec19d10dlFq
  38:        0x107d2595e - check::check_expr_with_unifier::h8674341778859500334
  39:        0x107d00d9c - check::check_argument_types::hbd54866e0651a010O5p
  40:        0x107cfe0be - check::callee::confirm_builtin_call::h98216b80db4bfd2f5qm
  41:        0x107cfc849 - check::callee::check_call::hf304e98e66e2eee3Nhm
  42:        0x107d49701 - check::check_expr_with_unifier::h4364205555285070129
  43:        0x107d191db - check::check_block_with_expected::h83c5e18f3456d9895hs
  44:        0x107cfa508 - check::check_fn::h5c814037ea8a2362C4n
  45:        0x107d14599 - check::check_bare_fn::hd839ee74cb29d084bUn
  46:        0x107d1d4c7 - check::check_method_body::hf8957dc76229cbd6Gvo
  47:        0x107d124db - check::CheckItemBodiesVisitor&lt;'a, 'tcx&gt;.Visitor&lt;'tcx&gt;::visit_item::hc008350ec16b94ffeRn
  48:        0x107ddbeda - check_crate::closure.38340
  49:        0x107dd72e7 - check_crate::h7f9bbce56981d322gCC
  50:        0x107b3c2d2 - driver::phase_3_run_analysis_passes::hb862dc042470f6e0nGa
  51:        0x107b1e09c - driver::compile_input::h4747d8bb1c595fdfQba
  52:        0x107be58f3 - run_compiler::hc8c95c5858347fdbz4b
  53:        0x107be341a - boxed::F.FnBox&lt;A&gt;::call_box::h7872786064439979928
  54:        0x107be28b7 - rt::unwind::try::try_fn::h10239991317224243769
  55:        0x10b0857c8 - rust_try_inner
  56:        0x10b0857b5 - rust_try
  57:        0x107be2b90 - boxed::F.FnBox&lt;A&gt;::call_box::h4543691575426869824
  58:        0x10b00348d - sys::thread::create::thread_start::h499b3be451a7bbb8AZu
  59:     0x7fff91f30267 - _pthread_body
  60:     0x7fff91f301e4 - _pthread_start"><pre class="notranslate"><code class="notranslate">thread 'rustc' panicked at 'Box&lt;Any&gt;', /Users/rustbuild/src/rust-buildbot/slave/beta-dist-rustc-mac/build/src/libsyntax/diagnostic.rs:149

stack backtrace:
   1:        0x10affc33f - sys::backtrace::write::h0f2fc53eb11eb814gWr
   2:        0x10b004942 - panicking::on_panic::hd617a4042e8486fciUv
   3:        0x10afc1375 - rt::unwind::begin_unwind_inner::hd84dfec22ac3667d1Bv
   4:        0x10a7a09fe - rt::unwind::begin_unwind::h17792509132866387090
   5:        0x10a7a098a - diagnostic::SpanHandler::span_bug::hebb6215f61f436aaEqB
   6:        0x10867405b - middle::infer::region_inference::RegionVarBindings&lt;'a, 'tcx&gt;::make_subregion::h4adb78ad460601ecS8u
   7:        0x10862aeab - middle::infer::sub::Sub&lt;'a, 'tcx&gt;.TypeRelation&lt;'a, 'tcx&gt;::regions::h3f9ee82a2e72a144Mjx
   8:        0x10862ac91 - middle::infer::sub::Sub&lt;'a, 'tcx&gt;.TypeRelation&lt;'a, 'tcx&gt;::relate_with_variance::h5672739467683317342
   9:        0x10862a20b - middle::ty_relate::relate_substs::h2389761154872115822
  10:        0x1086297fa - middle::ty_relate::relate_item_substs::h7360249961707336134
  11:        0x10868b447 - middle::ty_relate::super_relate_tys::h10795509169925483940
  12:        0x108621bb2 - middle::infer::sub::Sub&lt;'a, 'tcx&gt;.TypeRelation&lt;'a, 'tcx&gt;::tys::h3174a850422a5fc1pfx
  13:        0x10868ff47 - middle::infer::InferCtxt&lt;'a, 'tcx&gt;::sub_types::hea49ed0ad06eecf898y
  14:        0x107ccd1d5 - check::method::probe::ProbeContext&lt;'a, 'tcx&gt;::consider_candidates::h2b54d2790fd0880dXoi
  15:        0x107cccf79 - check::method::probe::ProbeContext&lt;'a, 'tcx&gt;::pick_method::hc768ec9b0fb6e87dUki
  16:        0x107ccc346 - check::method::probe::ProbeContext&lt;'a, 'tcx&gt;::pick_core::h3e5895ad5629b90bOfi
  17:        0x107cc1cbc - check::method::probe::probe::closure.31574
  18:        0x107cbf389 - check::method::probe::probe::hfbf147788d37ee49T4g
  19:        0x107cd9ecd - check::method::resolve_ufcs::h9a77d5ebe946bd48d7j
  20:        0x107d65c30 - check::check_expr_with_unifier::h1091590169474595220
  21:        0x107cfaf2c - check::callee::check_call::hf304e98e66e2eee3Nhm
  22:        0x107d61b0a - check::check_expr_with_unifier::h1091590169474595220
  23:        0x107d0a18d - check::op::check_binop::h6504e0630336d4baFan
  24:        0x107d498ae - check::check_expr_with_unifier::h4364205555285070129
  25:        0x107d0a42e - check::op::check_binop::h6504e0630336d4baFan
  26:        0x107d4343b - check::check_expr_with_unifier::h8963715346170232283
  27:        0x107d2f66d - check::check_expr_with_unifier::check_then_else::h1d5d0ab6867397defIq
  28:        0x107d49b8d - check::check_expr_with_unifier::h4364205555285070129
  29:        0x107d191db - check::check_block_with_expected::h83c5e18f3456d9895hs
  30:        0x107d49d85 - check::check_expr_with_unifier::h4364205555285070129
  31:        0x107d191db - check::check_block_with_expected::h83c5e18f3456d9895hs
  32:        0x107cfa508 - check::check_fn::h5c814037ea8a2362C4n
  33:        0x107cf8966 - check::closure::check_expr_closure::h0b5d1648c0a7d5409Pl
  34:        0x107d25f08 - check::check_expr_with_unifier::h8674341778859500334
  35:        0x107d00d9c - check::check_argument_types::hbd54866e0651a010O5p
  36:        0x107d0208a - check::check_method_argument_types::h42f31152b61f4a11d3p
  37:        0x107d308cc - check::check_expr_with_unifier::check_method_call::h6fc40daeec19d10dlFq
  38:        0x107d2595e - check::check_expr_with_unifier::h8674341778859500334
  39:        0x107d00d9c - check::check_argument_types::hbd54866e0651a010O5p
  40:        0x107cfe0be - check::callee::confirm_builtin_call::h98216b80db4bfd2f5qm
  41:        0x107cfc849 - check::callee::check_call::hf304e98e66e2eee3Nhm
  42:        0x107d49701 - check::check_expr_with_unifier::h4364205555285070129
  43:        0x107d191db - check::check_block_with_expected::h83c5e18f3456d9895hs
  44:        0x107cfa508 - check::check_fn::h5c814037ea8a2362C4n
  45:        0x107d14599 - check::check_bare_fn::hd839ee74cb29d084bUn
  46:        0x107d1d4c7 - check::check_method_body::hf8957dc76229cbd6Gvo
  47:        0x107d124db - check::CheckItemBodiesVisitor&lt;'a, 'tcx&gt;.Visitor&lt;'tcx&gt;::visit_item::hc008350ec16b94ffeRn
  48:        0x107ddbeda - check_crate::closure.38340
  49:        0x107dd72e7 - check_crate::h7f9bbce56981d322gCC
  50:        0x107b3c2d2 - driver::phase_3_run_analysis_passes::hb862dc042470f6e0nGa
  51:        0x107b1e09c - driver::compile_input::h4747d8bb1c595fdfQba
  52:        0x107be58f3 - run_compiler::hc8c95c5858347fdbz4b
  53:        0x107be341a - boxed::F.FnBox&lt;A&gt;::call_box::h7872786064439979928
  54:        0x107be28b7 - rt::unwind::try::try_fn::h10239991317224243769
  55:        0x10b0857c8 - rust_try_inner
  56:        0x10b0857b5 - rust_try
  57:        0x107be2b90 - boxed::F.FnBox&lt;A&gt;::call_box::h4543691575426869824
  58:        0x10b00348d - sys::thread::create::thread_start::h499b3be451a7bbb8AZu
  59:     0x7fff91f30267 - _pthread_body
  60:     0x7fff91f301e4 - _pthread_start
</code></pre></div>