With syntex feature

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "textnonce"
-version = "0.2.4"
+version = "0.2.5"
 description = "Text based random nonce generator"
 authors = [
         "Mike Dilger <[email protected]>",
@@ -13,13 +13,18 @@ license = "MIT OR Apache-2.0"
 keywords = [ "nonce", "random" ]
 build = "build.rs"
 
+[features]
+default = ["with-syntex"]
+with-syntex = ["syntex", "serde_codegen"]
+
 [build-dependencies]
-serde_codegen = "^0"
-syntex = "^0"
+serde_codegen = { version = "^0", optional = true }
+syntex = { version = "^0", optional = true }
 
 [dependencies]
 rand = "^0.3"
 time = "^0.1"
 rustc-serialize = "^0.3"
 serde = "^0"
-clippy = { version = "^0", optional = true }
+serde_macros = { version = "^0", optional = true }
+clippy = { version = "^0", optional = true }

build.rs

@@ -1,17 +1,29 @@
-extern crate syntex;
-extern crate serde_codegen;
+#[cfg(feature = "with-syntex")]
+mod inner {
+    extern crate syntex;
+    extern crate serde_codegen;
 
-use std::env;
-use std::path::Path;
+    use std::env;
+    use std::path::Path;
 
-fn main() {
-    let out_dir = env::var_os("OUT_DIR").unwrap();
+    pub fn main() {
+        let out_dir = env::var_os("OUT_DIR").unwrap();
+
+        let src = Path::new("src/lib.rs.in");
+        let dst = Path::new(&out_dir).join("lib.rs");
 
-    let src = Path::new("src/lib.rs.in");
-    let dst = Path::new(&out_dir).join("lib.rs");
+        let mut registry = syntex::Registry::new();
 
-    let mut registry = syntex::Registry::new();
+        serde_codegen::register(&mut registry);
+        registry.expand("", &src, &dst).unwrap();
+    }
+}
 
-    serde_codegen::register(&mut registry);
-    registry.expand("", &src, &dst).unwrap();
+#[cfg(not(feature = "with-syntex"))]
+mod inner {
+    pub fn main() {}
 }
+
+fn main() {
+    inner::main();
+}

src/lib.rs

@@ -8,9 +8,17 @@
 #![cfg_attr(feature="clippy", feature(plugin))]
 #![cfg_attr(feature="clippy", plugin(clippy))]
 
+#![cfg_attr(not(feature = "with-syntex"), feature(custom_attribute, custom_derive, plugin))]
+#![cfg_attr(not(feature = "with-syntex"), plugin(serde_macros))]
+
 extern crate rand;
 extern crate time;
 extern crate rustc_serialize;
 extern crate serde;
 
-include!(concat!(env!("OUT_DIR"), "/lib.rs"));
+
+#[cfg(not(feature = "with-syntex"))]
+include!("lib.rs.in");
+
+#[cfg(feature = "with-syntex")]
+include!(concat!(env!("OUT_DIR"), "/lib.rs"));