Fails silently: match 1 {1 => 3, 2u => 4}

[ssbr]

Putting that code somewhere in a project will result in a failure to build, but (at least in rust 0.6, on windows) no error message.

Consider this shell session in mingw:

$ cat > test_mod.rs
fn main() {match 1 {1 => 3, 2u => 4};}
$ rustc.exe test_mod.rs
$ echo $?
101
$ RUST_LOG=rustc=1,::rt::backtrace rustc.exe test_mod.rs
rust: task failed at 'compare_const_vals: ill-typed comparison', C:\bot\slave\dist-win\build\src\librustc\middle\const_eval.rs:477
rust: domain main @0x459278 root task failed

[bblum]

come on bors