5 files changed, 14 insertions, 13 deletions
diff --git a/components/script/dom/bindings/root.rs b/components/script/dom/bindings/root.rs
index 998a2bd2413..87525900448 100644
--- a/components/script/dom/bindings/root.rs
+++ b/components/script/dom/bindings/root.rs
@@ -39,8 +39,6 @@ use script_layout_interface::TrustedNodeAddress;
 use std::cell::{Cell, UnsafeCell};
 use std::default::Default;
 use std::hash::{Hash, Hasher};
-#[cfg(debug_assertions)]
-use std::intrinsics::type_name;
 use std::marker::PhantomData;
 use std::mem;
 use std::ops::Deref;
@@ -359,11 +357,11 @@ impl<T: DomObject> Deref for Dom<T> {
 
 unsafe impl<T: DomObject> JSTraceable for Dom<T> {
     unsafe fn trace(&self, trc: *mut JSTracer) {
-        #[cfg(debug_assertions)]
-        let trace_str = format!("for {} on heap", type_name::<T>());
-        #[cfg(debug_assertions)]
+        #[cfg(all(feature = "unstable", debug_assertions))]
+        let trace_str = format!("for {} on heap", ::std::intrinsics::type_name::<T>());
+        #[cfg(all(feature = "unstable", debug_assertions))]
         let trace_info = &trace_str[..];
-        #[cfg(not(debug_assertions))]
+        #[cfg(not(all(feature = "unstable", debug_assertions)))]
         let trace_info = "for DOM object on heap";
 
         trace_reflector(trc,
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index 1e4bf803427..136eb86c03b 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -805,6 +805,7 @@ impl WindowMethods for Window {
 
     #[allow(unsafe_code)]
     fn Trap(&self) {
+        #[cfg(feature = "unstable")]
         unsafe { ::std::intrinsics::breakpoint() }
     }
 
diff --git a/components/script/lib.rs b/components/script/lib.rs
index 28f4181b934..5f33f1e1151 100644
--- a/components/script/lib.rs
+++ b/components/script/lib.rs
@@ -2,10 +2,10 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#![cfg_attr(feature = "unstable", feature(core_intrinsics))]
 #![cfg_attr(feature = "unstable", feature(on_unimplemented))]
 #![feature(conservative_impl_trait)]
 #![feature(const_fn)]
-#![feature(core_intrinsics)]
 #![feature(mpsc_select)]
 #![feature(plugin)]
 #![feature(proc_macro)]
diff --git a/components/script/task.rs b/components/script/task.rs
index e90fc21c55c..eab786c8c20 100644
--- a/components/script/task.rs
+++ b/components/script/task.rs
@@ -5,7 +5,6 @@
 //! Machinery for [tasks](https://html.spec.whatwg.org/multipage/#concept-task).
 
 use std::fmt;
-use std::intrinsics;
 use std::sync::Arc;
 use std::sync::atomic::{AtomicBool, Ordering};
 
@@ -33,7 +32,10 @@ macro_rules! task {
 pub trait TaskOnce: Send {
     #[allow(unsafe_code)]
     fn name(&self) -> &'static str {
-        unsafe { intrinsics::type_name::<Self>() }
+        #[cfg(feature = "unstable")]
+        unsafe { ::std::intrinsics::type_name::<Self>() }
+        #[cfg(not(feature = "unstable"))]
+        { "(task name unknown)" }
     }
 
     fn run_once(self);
diff --git a/ports/servo/main.rs b/ports/servo/main.rs
index 19063d1176a..b24737f2d19 100644
--- a/ports/servo/main.rs
+++ b/ports/servo/main.rs
@@ -15,7 +15,7 @@
 //!
 //! [glutin]: https://github.com/tomaka/glutin
 
-#![feature(core_intrinsics)]
+#![cfg_attr(feature = "unstable", feature(core_intrinsics))]
 
 #[cfg(target_os = "android")]
 extern crate android_injected_glue;
@@ -26,7 +26,7 @@ extern crate glutin_app as app;
 extern crate log;
 // The Servo engine
 extern crate servo;
-#[cfg(not(target_os = "android"))]
+#[cfg(all(feature = "unstable", not(target_os = "android")))]
 #[macro_use]
 extern crate sig;
 
@@ -57,7 +57,7 @@ pub mod platform {
     pub fn deinit() {}
 }
 
-#[cfg(not(target_os = "android"))]
+#[cfg(all(feature = "unstable", not(target_os = "android")))]
 fn install_crash_handler() {
     use backtrace::Backtrace;
     use sig::ffi::Sig;
@@ -83,7 +83,7 @@ fn install_crash_handler() {
     signal!(Sig::BUS, handler); // handle invalid memory access
 }
 
-#[cfg(target_os = "android")]
+#[cfg(any(not(feature = "unstable"), target_os = "android"))]
 fn install_crash_handler() {}
 
 fn main() {