nightly cargo panics on --version

[durka]

On Linux and Mac:

$ rustup update
[...]
   nightly-x86_64-apple-darwin updated - rustc 1.17.0-nightly (a559452b0 2017-03-17)
$ RUST_BACKTRACE=1 cargo +nightly -V
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', src/libcore/option.rs:323
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
stack backtrace:
   0: cargo::version
   1: cargo::execute
   2: cargo::call_main_without_stdin
   3: cargo::main

[durka]

rust-lang/cargo#3844