{ "foo":
  { "type": ["@", "rules-rust", "rust", "library"]
  , "name": ["foo"]
  , "crate_root": ["foo.rs"]
  , "c_hdrs": ["foo.h"]
  , "stage": ["foo"]
  , "deps": ["bar"]
  }
, "bar":
  { "type": ["@", "rules-rust", "rust", "library"]
  , "name": ["bar"]
  , "crate_root": ["bar.rs"]
  , "stage": ["bar"]
  }
}