Cargo errors out on "cargo check"

[RalfJung]

After installing cargo-check, when I try to use it, I get the following error:

$ PATH=$HOME/r/.cargo/bin:$PATH cargo check
error: extra arguments to `rustc` can only be passed to one target, consider filtering
the package by passing e.g. `--lib` or `--bin NAME` to specify a single target
error: third party subcommand `cargo-check` exited unsuccessfully

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

This is with

$ rustc --version
rustc 1.9.0-beta.1 (37a2869af 2016-04-12)

but I already saw this with the 1.8 betas.

[shepmaster]

Duplicate of #4

[rsolomo]

closing due to being a duplicate of #4