proc-macro2-0.1.10 build error

[ghost]

OS: Debian 9 / Alpine Linux 3.7
cargo 0.24.0 (45043115c 2017-12-05) / 0.22.0-r3

dns@dns:~# sudo cargo install doh-proxy
    Updating registry `https://github.com/rust-lang/crates.io-index`
  Installing doh-proxy v0.1.2
 Downloading tokio-io v0.1.5
 Downloading hyper v0.11.18
   Compiling take v0.1.0
   Compiling futures-await-await-macro v0.1.0
   Compiling futures v0.1.18
   Compiling unicode-width v0.1.4
   Compiling smallvec v0.2.1
   Compiling bitflags v1.0.1
   Compiling version_check v0.1.3
   Compiling ansi_term v0.10.2
   Compiling strsim v0.7.0
   Compiling scoped-tls v0.1.0
   Compiling slab v0.3.0
   Compiling safemem v0.2.0
   Compiling libc v0.2.36
   Compiling slab v0.4.0
   Compiling unicode-xid v0.1.0
   Compiling language-tags v0.2.2
   Compiling httparse v1.2.4
   Compiling lazycell v0.6.0
   Compiling vec_map v0.8.0
   Compiling percent-encoding v1.0.1
   Compiling byteorder v1.2.1
   Compiling cfg-if v0.1.2
   Compiling textwrap v0.9.0
   Compiling unicase v2.1.0
   Compiling tokio-service v0.1.0
   Compiling relay v0.1.1
   Compiling tokio-timer v0.1.2
   Compiling proc-macro2 v0.1.10
error[E0554]: #![feature] may not be used on the stable release channel
  --> .cargo/registry/src/github.com-1ecc6299db9ec823/proc-macro2-0.1.10/src/lib.rs:22:34
   |
22 | #![cfg_attr(feature = "nightly", feature(proc_macro))]
   |                                  ^^^^^^^^^^^^^^^^^^^^

error: aborting due to previous error

error: Could not compile `proc-macro2`.
warning: build failed, waiting for other jobs to finish...
error: failed to compile `doh-proxy v0.1.2`, intermediate artifacts can be found at `/tmp/cargo-install.oUYH9w39z3Qu`

Caused by:
  build failed