`cargo test` doesn't seem to work with rust HEAD

[erickt]

Something seems to have broken cargo test. Here's an example:

% git clone https://github.com/erickt/rust-zmq
% cd rust-zmq
% cargo test --verbose
     Running `rustc src/zmq/lib.rs --crate-name zmq --crate-type lib --test -C metadata=zmq:-:0.5.1:-:file:/private/tmp/rust-zmq -C extra-filename=-69bf4070b483a156 --out-dir /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test/deps`
     Running `rustc src/zmq/lib.rs --crate-name zmq --crate-type lib -C metadata=zmq:-:0.5.1:-:file:/private/tmp/rust-zmq -C extra-filename=-69bf4070b483a156 --out-dir /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test/deps`
     Running `rustc examples/msgsend/main.rs --crate-name msgsend --crate-type bin --out-dir /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test/deps`
     Running `rustc examples/zguide/helloworld-client/main.rs --crate-name helloworld-client --crate-type bin --out-dir /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test/deps`
     Running `rustc examples/zguide/helloworld-server/main.rs --crate-name helloworld-server --crate-type bin --out-dir /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test/deps`
     Running `rustc examples/zguide/version/main.rs --crate-name version --crate-type bin --out-dir /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test/deps`
     Running `rustc examples/zguide/weather-client/main.rs --crate-name weather-client --crate-type bin --out-dir /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test/deps`
     Running `rustc examples/zguide/weather-server/main.rs --crate-name weather-server --crate-type bin --out-dir /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test -L /private/tmp/rust-zmq/target/test/deps`
   Compiling zmq v0.5.1 (file:/private/tmp/rust-zmq)
src/zmq/lib.rs:654:29: 654:41 warning: use of deprecated item: Replaced by `to_vec`, #[warn(deprecated)] on by default
src/zmq/lib.rs:654         self.with_bytes(|v| v.to_owned())
                                               ^~~~~~~~~~~~
src/zmq/lib.rs:654:29: 654:41 warning: use of deprecated item: Replaced by `to_vec`, #[warn(deprecated)] on by default
src/zmq/lib.rs:654         self.with_bytes(|v| v.to_owned())
                                               ^~~~~~~~~~~~
An unknown error occurred

Caused by:
  Could not execute process `/private/tmp/rust-zmq/target/test/zmq` (status=never executed)

Caused by:
  no such file or directory

The problem is that cargo is generating target/test/zmq-69bf4070b483a156, but cargo test seems to be looking for target/test/zmq. This is probably an issue in rust, as cargo works fine with the current rust-nightly. @sfackler tracked down @alexcrichton's rust-lang/rust#15686 as being a potential source of this bug.

[netvl]

Now it does not work with the latest nightly too.

[SimonSapin]

I can reproduce this in rust-url. Note that Cargo seems to add -C extra-filename=-7f74b19126a4ded7 to rustc command-line arguments. Running the same command without that argument creates a file with the expected filename. (Here, target/test/url_.)

$ cargo test --verbose
     Running `rustc src/encoding/lib.rs --crate-name encoding --crate-type lib -C metadata=encoding:-:0.1.0:-:https://github.com/lifthrasiir/rust-encoding -C extra-filename=-0d3aa218cf637ede --out-dir /home/simon/projects/rust-url/target/test/deps -L /home/simon/projects/rust-url/target/test/deps -L /home/simon/projects/rust-url/target/test/deps`
     Running `rustc src/url.rs --crate-name url_ --crate-type lib --test -C metadata=url:-:0.1.0:-:file:/home/simon/projects/rust-url -C extra-filename=-7f74b19126a4ded7 --out-dir /home/simon/projects/rust-url/target/test -L /home/simon/projects/rust-url/target/test -L /home/simon/projects/rust-url/target/test/deps --extern encoding=/home/simon/projects/rust-url/target/test/deps/libencoding-0d3aa218cf637ede.rlib`
     Running `rustc src/url.rs --crate-name url_ --crate-type lib -C metadata=url:-:0.1.0:-:file:/home/simon/projects/rust-url -C extra-filename=-7f74b19126a4ded7 --out-dir /home/simon/projects/rust-url/target/test -L /home/simon/projects/rust-url/target/test -L /home/simon/projects/rust-url/target/test/deps --extern encoding=/home/simon/projects/rust-url/target/test/deps/libencoding-0d3aa218cf637ede.rlib`
   Compiling encoding v0.1.0 (https://github.com/lifthrasiir/rust-encoding)
   Compiling url v0.1.0 (file:/home/simon/projects/rust-url)
An unknown error occurred

Caused by:
  Could not execute process `/home/simon/projects/rust-url/target/test/url_` (status=never executed)

Caused by:
  no such file or directory

$ ls target/test
deps/  liburl_-7f74b19126a4ded7.rlib  native/  url_-7f74b19126a4ded7*