<p dir="auto">I tried to compile a simple <code class="notranslate">hello.rs</code> and ran into the following - output below after turning on <code class="notranslate">RUST_BACKTRACE=1</code>:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="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 'needs a temp dir', /home/rustbuild/src/rust-buildbot/slave/dist2-linux/build/src/libcore/option.rs:315

stack backtrace:
   1: 0xb6a79d00 - rt::backtrace::imp::write::h71c0311871d92b33BCq
   2: 0xb6a7cc80 - &lt;unknown&gt;
   3: 0xb6dc6c50 - unwind::begin_unwind_inner::hecb213f6de4ee4abIxd
   4: 0xb6dc68b0 - unwind::begin_unwind_fmt::h14c200c16a264a5eavd
   5: 0xb6dc6850 - rust_begin_unwind
   6: 0xb6e16530 - failure::fail_fmt::h767d9e1ca2333a4biqk
   7: 0xb6f63b80 - &lt;unknown&gt;
   8: 0xb6f5a2b0 - back::link::link_binary::hf1d7c6859ef3a2c6xBa
   9: 0xb782d2f0 - driver::driver::phase_6_link_output::he5609548684fab17h2w
  10: 0xb7824590 - driver::driver::compile_input::h665973ab72cfb8bbKww
  11: 0xb78a89d0 - &lt;unknown&gt;
  12: 0xb78a88a0 - &lt;unknown&gt;
  13: 0xb6f8a8f0 - &lt;unknown&gt;
  14: 0xb6f8a6e0 - &lt;unknown&gt;
  15: 0xb7fc2550 - &lt;unknown&gt;
  16: 0xb6dc6660 - &lt;unknown&gt;
  17: 0xb6e26110 - &lt;unknown&gt;
  18: 0xb6e260d0 - rust_try
  19: 0xb6dc4780 - unwind::try::h38aefa52248da233qmd
  20: 0xb6dc45f0 - task::Task::run::h52211e2f40072d874Bc
  21: 0xb7fc22f0 - &lt;unknown&gt;
  22: 0xb6dc5da0 - &lt;unknown&gt;
  23:        0x0 - &lt;unknown&gt;"><pre class="notranslate"><code class="notranslate">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 'needs a temp dir', /home/rustbuild/src/rust-buildbot/slave/dist2-linux/build/src/libcore/option.rs:315

stack backtrace:
   1: 0xb6a79d00 - rt::backtrace::imp::write::h71c0311871d92b33BCq
   2: 0xb6a7cc80 - &lt;unknown&gt;
   3: 0xb6dc6c50 - unwind::begin_unwind_inner::hecb213f6de4ee4abIxd
   4: 0xb6dc68b0 - unwind::begin_unwind_fmt::h14c200c16a264a5eavd
   5: 0xb6dc6850 - rust_begin_unwind
   6: 0xb6e16530 - failure::fail_fmt::h767d9e1ca2333a4biqk
   7: 0xb6f63b80 - &lt;unknown&gt;
   8: 0xb6f5a2b0 - back::link::link_binary::hf1d7c6859ef3a2c6xBa
   9: 0xb782d2f0 - driver::driver::phase_6_link_output::he5609548684fab17h2w
  10: 0xb7824590 - driver::driver::compile_input::h665973ab72cfb8bbKww
  11: 0xb78a89d0 - &lt;unknown&gt;
  12: 0xb78a88a0 - &lt;unknown&gt;
  13: 0xb6f8a8f0 - &lt;unknown&gt;
  14: 0xb6f8a6e0 - &lt;unknown&gt;
  15: 0xb7fc2550 - &lt;unknown&gt;
  16: 0xb6dc6660 - &lt;unknown&gt;
  17: 0xb6e26110 - &lt;unknown&gt;
  18: 0xb6e260d0 - rust_try
  19: 0xb6dc4780 - unwind::try::h38aefa52248da233qmd
  20: 0xb6dc45f0 - task::Task::run::h52211e2f40072d874Bc
  21: 0xb7fc22f0 - &lt;unknown&gt;
  22: 0xb6dc5da0 - &lt;unknown&gt;
  23:        0x0 - &lt;unknown&gt;
</code></pre></div>
<p dir="auto"><code class="notranslate">hello.rs</code> is a simple calculator demo program found on rust-lang.org.</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="$ rustc --version
rustc 0.12.0 (ba4081a5a 2014-10-07 13:44:41 -0700)"><pre class="notranslate"><code class="notranslate">$ rustc --version
rustc 0.12.0 (ba4081a5a 2014-10-07 13:44:41 -0700)
</code></pre></div>
<p dir="auto">Please let me know if you need more information.</p>
<p dir="auto">When compiling without a valid temp directory (i.e. TMPDIR environment variable) rustc issues the following error:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="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 'needs a temp dir', /path/to/rust/src/libstd/option.rs:167"><pre class="notranslate"><code class="notranslate">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 'needs a temp dir', /path/to/rust/src/libstd/option.rs:167
</code></pre></div>