<std macros>:8:12: 95:21 error: cannot apply unary operator ! to type &'static str, then compiler error

[crispweed]

When I try running the tests for rust-doom, I get the following:

~/rust/projects/doom $ cargo test
   Compiling toml v0.1.0 (https://github.com/alexcrichton/toml-rs#8a3ba4c6)
   Compiling khronos_api v0.0.1 (https://github.com/bjz/gl-rs#feed7be3)
   Compiling rust-xml v0.1.0 (https://github.com/netvl/rust-xml#f86f02b3)
   Compiling sdl2 v0.0.1-alpha.1 (https://github.com/cristicbz/rust-sdl2?ref=static_to_const#c8c36cb6)
   Compiling gl_generator v0.0.1 (https://github.com/bjz/gl-rs#feed7be3)
   Compiling gl v0.0.1 (https://github.com/bjz/gl-rs#feed7be3)
   Compiling rs-doom v0.0.7 (file:///home/thomas/rust/projects/doom)
<std macros>:8:12: 95:21 error: cannot apply unary operator `!` to type `&'static str`
<std macros>:8         if !$cond {
<std macros>:9             fail!($($arg),+)
<std macros>:10         }
<std macros>:11     );
<std macros>:12 )
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 'index out of bounds: the len is 12 but the index is 12', /home/rustbuild/src/rust-buildbot/slave/nightly-linux/build/src/libsyntax/lib.rs:1


Could not compile `rs-doom`.

To learn more, run the command again with --verbose.

This is on Linux Mint 17, x64.

~/rust $ rustc --version
rustc 0.13.0-nightly (adb44f53d 2014-10-12 00:07:15 +0000)

There's no error when just building the project, this only occurs when running the tests.
I'm new to rust and couldn't see how to add RUST_BACKTRACE=1 in the context of running tests, or how to compile files individually with the same compiler settings as for cargo test in order to narrow the problem down..

[alexcrichton]

Closing as a dupe of #14091