From e541b2ece9951fb00612e4fc14739634725cbf36 Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Mon, 30 Sep 2019 13:44:13 +0200
Subject: [PATCH 1/2] Add E0551 long error explanation

---
 src/libsyntax/error_codes.rs | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/libsyntax/error_codes.rs b/src/libsyntax/error_codes.rs
index 8a78daee6e49b..b0b898eccd6f7 100644
--- a/src/libsyntax/error_codes.rs
+++ b/src/libsyntax/error_codes.rs
@@ -163,6 +163,25 @@ fn the_banished() {} // ok!
 ```
 "##,
 
+E0551: r##"
+An invalid meta-item was used inside an attribute.
+
+Erroneous code example:
+
+```compile_fail,E0551
+#[deprecated(note)] // error!
+fn i_am_deprecated() {}
+```
+
+Meta items are the key-value pairs inside of an attribute. To fix this issue,
+you need to give a value to the `note` key. Example:
+
+```
+#[deprecated(note = "because")] // ok!
+fn i_am_deprecated() {}
+```
+"##,
+
 E0552: r##"
 A unrecognized representation attribute was used.
 
@@ -454,7 +473,6 @@ features in the `-Z allow_features` flag.
     // rustc_deprecated attribute must be paired with either stable or unstable
     // attribute
     E0549,
-    E0551, // incorrect meta item
     E0553, // multiple rustc_const_unstable attributes
 //  E0555, // replaced with a generic attribute input check
     E0556, // malformed feature, expected just one word

From 62f1fb33ec02d59d5984584fd4d04b0443af632b Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Mon, 30 Sep 2019 13:44:23 +0200
Subject: [PATCH 2/2] Update ui tests

---
 src/test/ui/deprecation/deprecation-sanity.stderr | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/test/ui/deprecation/deprecation-sanity.stderr b/src/test/ui/deprecation/deprecation-sanity.stderr
index 15afa78b140d5..57143d6810554 100644
--- a/src/test/ui/deprecation/deprecation-sanity.stderr
+++ b/src/test/ui/deprecation/deprecation-sanity.stderr
@@ -54,5 +54,5 @@ LL | #[deprecated(since = "a", since = "b", note = "c")]
 
 error: aborting due to 9 previous errors
 
-Some errors have detailed explanations: E0538, E0541, E0550, E0565.
+Some errors have detailed explanations: E0538, E0541, E0550, E0551, E0565.
 For more information about an error, try `rustc --explain E0538`.