Rust OpenSSL crate 在 Mac OS X 10.11 上编译失败

我试图在Mac OS X 10.11.2上安装铁 rust 框架，但在编译openssl的东西时运行cargo build或cargo run失败:

failed to run custom build command for `openssl-sys-extras v0.7.4`
Process didn't exit successfully: `/xxx/rust/hello/target/debug/build/openssl-sys-extras-413d6c73b37a590d/build-script-build` (exit code: 101)
--- stdout
TARGET = Some("x86_64-apple-darwin")
OPT_LEVEL = Some("0")
PROFILE = Some("debug")
TARGET = Some("x86_64-apple-darwin")
debug=true opt-level=0
HOST = Some("x86_64-apple-darwin")
TARGET = Some("x86_64-apple-darwin")
TARGET = Some("x86_64-apple-darwin")
HOST = Some("x86_64-apple-darwin")
CC_x86_64-apple-darwin = None
CC_x86_64_apple_darwin = None
HOST_CC = None
CC = None
HOST = Some("x86_64-apple-darwin")
TARGET = Some("x86_64-apple-darwin")
HOST = Some("x86_64-apple-darwin")
CFLAGS_x86_64-apple-darwin = None
CFLAGS_x86_64_apple_darwin = None
HOST_CFLAGS = None
CFLAGS = None
running: "cc" "-O0" "-ffunction-sections" "-fdata-sections" "-g" "-m64" "-fPIC" "-o" "/xxx/rust/hello/target/debug/build/openssl-sys-extras-413d6c73b37a590d/out/src/openssl_shim.o" "-c" "src/openssl_shim.c"
ExitStatus(Code(1))


command did not execute successfully, got: exit code: 1



--- stderr
src/openssl_shim.c:1:10: fatal error: 'openssl/hmac.h' file not found
#include <openssl/hmac.h>
     ^
1 error generated.
thread '<main>' panicked at 'explicit panic', /xxx/.cargo/registry/src/github.com-0a35038f75765ae4/gcc-0.3.21/src/lib.rs:772

openssl版似乎还可以:

$ openssl version
OpenSSL 0.9.8zg 14 July 2015

我不知道我要做什么才能让这个安装工作，并try 一下熨斗.