cargo bloat has broken

[ah-]

Not sure what changed, but the travis builds fail with this:

The command "cargo fmt --all -- --write-mode=diff" exited with 0.
$ make bloat
xargo bloat --target thumbv7m-none-eabi  -n 50
   Compiling core v0.0.0 (file:///home/travis/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libcore)
    Finished release [optimized + debuginfo] target(s) in 42.60 secs
   Compiling compiler_builtins v0.1.0 (file:///home/travis/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libcompiler_builtins)
    Finished release [optimized + debuginfo] target(s) in 4.34 secs
error: Invalid arguments.
Usage: cargo bloat [options]
make: *** [bloat] Error 1

Going to remove it from travis until we figure out what's wrong.

It's working fine for me locally, but I'm not on the latest nightly.

[hdhoang]

Looks like this is rust-lang/cargo#5212, and fixed by rust-lang/rust#49182