Cargo build error

gistfile1.txt

λ cargo build --verbose 
   Compiling quasi v0.3.2
     Running `rustc /Users/julien/.cargo/registry/src/github.com-0a35038f75765ae4/quasi-0.3.2/src/lib.rs --crate-name quasi --crate-type lib -g -C metadata=1fdecb603ecbb4c6 -C extra-filename=-1fdecb603ecbb4c6 --out-dir /Users/julien/Code/soccer/target/debug/deps --emit=dep-info,link -L dependency=/Users/julien/Code/soccer/target/debug/deps -L dependency=/Users/julien/Code/soccer/target/debug/deps -Awarnings`
   Compiling aster v0.4.5
     Running `rustc /Users/julien/.cargo/registry/src/github.com-0a35038f75765ae4/aster-0.4.5/src/lib.rs --crate-name aster --crate-type lib -g -C metadata=2a46d4b73f937fb9 -C extra-filename=-2a46d4b73f937fb9 --out-dir /Users/julien/Code/soccer/target/debug/deps --emit=dep-info,link -L dependency=/Users/julien/Code/soccer/target/debug/deps -L dependency=/Users/julien/Code/soccer/target/debug/deps -Awarnings`
       Fresh pkg-config v0.3.5
       Fresh gcc v0.3.13
       Fresh winapi-build v0.1.1
       Fresh matches v0.1.2
       Fresh winapi v0.2.3
       Fresh typeable v0.1.2
       Fresh traitobject v0.0.1
       Fresh rustc-serialize v0.3.16
       Fresh unicase v1.0.0
       Fresh lazy_static v0.1.14
       Fresh bitflags v0.3.2
       Fresh language-tags v0.0.7
       Fresh libc v0.1.10
       Fresh httparse v0.1.6
       Fresh url v0.2.37
       Fresh log v0.3.2
       Fresh num_cpus v0.2.6
       Fresh hpack v0.2.0
       Fresh mime v0.1.0
       Fresh openssl-sys v0.6.5
       Fresh kernel32-sys v0.1.4
       Fresh advapi32-sys v0.1.2
       Fresh solicit v0.4.4
       Fresh openssl v0.6.5
       Fresh time v0.1.32
       Fresh rand v0.3.11
       Fresh cookie v0.1.21
       Fresh num v0.1.27
       Fresh hyper v0.6.13
       Fresh serde v0.6.0
/Users/julien/.cargo/registry/src/github.com-0a35038f75765ae4/quasi-0.3.2/src/lib.rs:11:43: 11:66 error: #[feature] may not be used on the stable release channel
/Users/julien/.cargo/registry/src/github.com-0a35038f75765ae4/quasi-0.3.2/src/lib.rs:11 #![cfg_attr(not(feature = "with-syntex"), feature(rustc_private))]
                                                                                                                                  ^~~~~~~~~~~~~~~~~~~~~~~
error: aborting due to previous error
Build failed, waiting for other jobs to finish...
/Users/julien/.cargo/registry/src/github.com-0a35038f75765ae4/aster-0.4.5/src/lib.rs:1:43: 1:66 error: #[feature] may not be used on the stable release channel
/Users/julien/.cargo/registry/src/github.com-0a35038f75765ae4/aster-0.4.5/src/lib.rs:1 #![cfg_attr(not(feature = "with-syntex"), feature(rustc_private))]
                                                                                                                                 ^~~~~~~~~~~~~~~~~~~~~~~
error: aborting due to previous error
Could not compile `quasi`.

Caused by:
  Process didn't exit successfully: `rustc /Users/julien/.cargo/registry/src/github.com-0a35038f75765ae4/quasi-0.3.2/src/lib.rs --crate-name quasi --crate-type lib -g -C metadata=1fdecb603ecbb4c6 -C extra-filename=-1fdecb603ecbb4c6 --out-dir /Users/julien/Code/soccer/target/debug/deps --emit=dep-info,link -L dependency=/Users/julien/Code/soccer/target/debug/deps -L dependency=/Users/julien/Code/soccer/target/debug/deps -Awarnings` (exit code: 101)