Make unused-extern-crate warn-by-default

diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index cbe642a9a76a65b3afca29288f97de502778745e..811bf9776101d4d5e0fd453d5e68c97a5e6e98b7 100644 (file)
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -30,7 +30,7 @@
 
 declare_lint! {
     pub UNUSED_EXTERN_CRATES,
-    Allow,
+    Warn,
     "extern crates that are never used"
 }