A pants owned rustup installation could not be found, installing via the instructions at <https://www.rustup.rs> ...
info: downloading installer
info: syncing channel updates for 'nightly-x86_64-apple-darwin'
info: downloading component 'rustc'
 44.1 MiB /  44.1 MiB (100 %)   4.1 MiB/s ETA:   0 s                
info: downloading component 'rust-std'
 57.3 MiB /  57.3 MiB (100 %)   7.5 MiB/s ETA:   0 s                
info: downloading component 'cargo'
info: installing component 'rustc'
info: installing component 'rust-std'
info: installing component 'cargo'
info: default toolchain set to 'nightly'

  nightly installed - rustc 1.17.0-nightly (413a975e3 2017-02-23)

info: using existing install for 'nightly-x86_64-apple-darwin'
info: override toolchain for '/Users/kwilson/dev/pants' set to 'nightly-x86_64-apple-darwin'

  nightly-x86_64-apple-darwin unchanged - rustc 1.17.0-nightly (413a975e3 2017-02-23)

    Updating git repository `<https://github.com/stuhood/futures-rs>`
    Updating registry `<https://github.com/rust-lang/crates.io-index>`
 Downloading crossbeam v0.2.10
 Downloading lazy_static v0.2.2
 Downloading fnv v1.0.5
 Downloading num_cpus v1.2.1
 Downloading log v0.3.6
 Downloading libc v0.2.20
   Compiling engine v0.0.1 (file:///Users/kwilson/dev/pants/src/rust/engine)
error: use of unstable library feature 'alloc_system': this library is unlikely to be stabilized in its current form or name (see issue #27783)
 --> src/rust/engine/src/core.rs:5:1
  |
5 | extern crate alloc_system;
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = help: add #![feature(alloc_system)] to the crate attributes to enable

error: aborting due to previous error

error: Could not compile `engine`.

To learn more, run the command again with --verbose.
cp: fts_open: No such file or directory
Pants 1.3.0.dev10 <https://pypi.python.org/pypi/pantsbuild.pants/1.3.0.dev10>

Usage:
  ./pants [option ...] [goal ...] [target...]  Attempt the specified goals.
…