<p dir="auto"><a href="https://gist.github.com/adudney/f5f45c705840406bb8ec">https://gist.github.com/adudney/f5f45c705840406bb8ec</a></p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="% uname -a 
Darwin pair 14.1.0 Darwin Kernel Version 14.1.0: Mon Dec 22 23:10:38 PST 2014; root:xnu-2782.10.72~2/RELEASE_X86_64 x86_64

% rustc --version --verbose
rustc 1.0.0-dev (a45e11773 2015-01-28 11:01:36 +0000)
binary: rustc
commit-hash: a45e117733b866302fa99390553d1c548508dcca
commit-date: 2015-01-28 11:01:36 +0000
host: x86_64-apple-darwin
release: 1.0.0-dev

% RUST_BACKTRACE=1 rustc --cfg=test rs_ffi_utils.rs
rs_ffi_utils.rs:236:1: 248:2 error: internal compiler error: coherence failed to report ambiguity: cannot locate the impl of the trait `MemWrite` for the type `Seq&lt;&amp;'o T&gt;`
rs_ffi_utils.rs:236 impl&lt;'o, T&gt; MemWrite for Seq&lt;&amp;'o T&gt; where T: Blob, &amp;'o T: MemWrite {
rs_ffi_utils.rs:237     fn write_to_mem&lt;'a&gt;(&amp;self, dst: &amp;'a mut [u8]) -&gt; Result&lt;&amp;'a [u8], MemAreaError&gt; {
rs_ffi_utils.rs:238         Ok(dst)
rs_ffi_utils.rs:239     }
rs_ffi_utils.rs:240
rs_ffi_utils.rs:241     fn size_required(&amp;self) -&gt; usize {
                    ...
note: the compiler unexpectedly panicked. 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
thread 'rustc' panicked at 'Box&lt;Any&gt;', /Users/swizard/distr/rust/src/libsyntax/diagnostic.rs:130

stack backtrace:
   1:        0x10dda37a7 - sys::backtrace::write::ha7c2a314980a2c9fvbu
   2:        0x10ddc9c5c - failure::on_fail::h6e454f5b61899a9aqbB
   3:        0x10dd2b068 - rt::unwind::begin_unwind_inner::h197e2c88eee2bed0mTA
   4:        0x10d4b2897 - rt::unwind::begin_unwind::h2026034157403174692
   5:        0x10d4b282c - diagnostic::SpanHandler::span_bug::hd1799d165b9b1455PGE
   6:        0x10aff6d1a - middle::traits::error_reporting::report_fulfillment_errors::hea46febf461f61d7YHN
   7:        0x10a95ed38 - check::vtable::select_all_fcx_obligations_or_error::h76d8a7711ec3b289Upb
   8:        0x10a9da0ae - check::wf::CheckTypeWellFormedVisitor&lt;'ccx, 'tcx&gt;::check_item_well_formed::h1acd04dfde9bfc73a7i
   9:        0x10aac784e - check_crate::closure.32081
  10:        0x10aac2e0f - check_crate::haecc3fe6465ec7b6ZNy
  11:        0x10a48c8eb - driver::phase_3_run_analysis_passes::h79664d81b6b5b4e4NFa
  12:        0x10a472e5c - driver::compile_input::hec1fc484fb82a3b3Bba
  13:        0x10a53b50e - run_compiler::hc5f9e0285db79a55n9b
  14:        0x10a53862f - thunk::F.Invoke&lt;A, R&gt;::invoke::h4736678281155978274
  15:        0x10a5372c0 - rt::unwind::try::try_fn::h3346791736825056138
  16:        0x10de42a09 - rust_try_inner
  17:        0x10de429f6 - rust_try
  18:        0x10a537984 - thunk::F.Invoke&lt;A, R&gt;::invoke::h14937575134341006880
  19:        0x10ddb4313 - sys::thread::thread_start::hd065b218eff37dc2J3w
  20:     0x7fff87bec268 - _pthread_body
  21:     0x7fff87bec1e5 - _pthread_body"><pre class="notranslate"><code class="notranslate">% uname -a 
Darwin pair 14.1.0 Darwin Kernel Version 14.1.0: Mon Dec 22 23:10:38 PST 2014; root:xnu-2782.10.72~2/RELEASE_X86_64 x86_64

% rustc --version --verbose
rustc 1.0.0-dev (a45e11773 2015-01-28 11:01:36 +0000)
binary: rustc
commit-hash: a45e117733b866302fa99390553d1c548508dcca
commit-date: 2015-01-28 11:01:36 +0000
host: x86_64-apple-darwin
release: 1.0.0-dev

% RUST_BACKTRACE=1 rustc --cfg=test rs_ffi_utils.rs
rs_ffi_utils.rs:236:1: 248:2 error: internal compiler error: coherence failed to report ambiguity: cannot locate the impl of the trait `MemWrite` for the type `Seq&lt;&amp;'o T&gt;`
rs_ffi_utils.rs:236 impl&lt;'o, T&gt; MemWrite for Seq&lt;&amp;'o T&gt; where T: Blob, &amp;'o T: MemWrite {
rs_ffi_utils.rs:237     fn write_to_mem&lt;'a&gt;(&amp;self, dst: &amp;'a mut [u8]) -&gt; Result&lt;&amp;'a [u8], MemAreaError&gt; {
rs_ffi_utils.rs:238         Ok(dst)
rs_ffi_utils.rs:239     }
rs_ffi_utils.rs:240
rs_ffi_utils.rs:241     fn size_required(&amp;self) -&gt; usize {
                    ...
note: the compiler unexpectedly panicked. 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
thread 'rustc' panicked at 'Box&lt;Any&gt;', /Users/swizard/distr/rust/src/libsyntax/diagnostic.rs:130

stack backtrace:
   1:        0x10dda37a7 - sys::backtrace::write::ha7c2a314980a2c9fvbu
   2:        0x10ddc9c5c - failure::on_fail::h6e454f5b61899a9aqbB
   3:        0x10dd2b068 - rt::unwind::begin_unwind_inner::h197e2c88eee2bed0mTA
   4:        0x10d4b2897 - rt::unwind::begin_unwind::h2026034157403174692
   5:        0x10d4b282c - diagnostic::SpanHandler::span_bug::hd1799d165b9b1455PGE
   6:        0x10aff6d1a - middle::traits::error_reporting::report_fulfillment_errors::hea46febf461f61d7YHN
   7:        0x10a95ed38 - check::vtable::select_all_fcx_obligations_or_error::h76d8a7711ec3b289Upb
   8:        0x10a9da0ae - check::wf::CheckTypeWellFormedVisitor&lt;'ccx, 'tcx&gt;::check_item_well_formed::h1acd04dfde9bfc73a7i
   9:        0x10aac784e - check_crate::closure.32081
  10:        0x10aac2e0f - check_crate::haecc3fe6465ec7b6ZNy
  11:        0x10a48c8eb - driver::phase_3_run_analysis_passes::h79664d81b6b5b4e4NFa
  12:        0x10a472e5c - driver::compile_input::hec1fc484fb82a3b3Bba
  13:        0x10a53b50e - run_compiler::hc5f9e0285db79a55n9b
  14:        0x10a53862f - thunk::F.Invoke&lt;A, R&gt;::invoke::h4736678281155978274
  15:        0x10a5372c0 - rt::unwind::try::try_fn::h3346791736825056138
  16:        0x10de42a09 - rust_try_inner
  17:        0x10de429f6 - rust_try
  18:        0x10a537984 - thunk::F.Invoke&lt;A, R&gt;::invoke::h14937575134341006880
  19:        0x10ddb4313 - sys::thread::thread_start::hd065b218eff37dc2J3w
  20:     0x7fff87bec268 - _pthread_body
  21:     0x7fff87bec1e5 - _pthread_body
</code></pre></div>