From fa5be237c5268810c1a677a28a21fa227d0a54a7 Mon Sep 17 00:00:00 2001
From: Manish Goregaokar <manishsmail@gmail.com>
Date: Mon, 5 Feb 2018 10:28:17 -0500
Subject: [PATCH] Feature gate epoches

---
 src/cargo/core/features.rs | 3 +++
 src/cargo/util/toml/mod.rs | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/src/cargo/core/features.rs b/src/cargo/core/features.rs
index 30c2b433f..10597e55e 100644
--- a/src/cargo/core/features.rs
+++ b/src/cargo/core/features.rs
@@ -146,6 +146,9 @@ features! {
 
         // Downloading packages from alternative registry indexes.
         [unstable] alternative_registries: bool,
+
+        // Using epochs
+        [unstable] epoch: bool,
     }
 }
 
diff --git a/src/cargo/util/toml/mod.rs b/src/cargo/util/toml/mod.rs
index d2e47a692..623d794af 100644
--- a/src/cargo/util/toml/mod.rs
+++ b/src/cargo/util/toml/mod.rs
@@ -718,6 +718,9 @@ impl TomlManifest {
         };
 
         let epoch = if let Some(ref epoch) = project.epoch {
+            features.require(Feature::epoch()).chain_err(|| {
+                "epoches are unstable"
+            })?;
             if let Ok(epoch) = epoch.parse() {
                 epoch
             } else {
-- 
2.30.2