Auto merge of #31643 - Manishearth:rollup, r=Manishearth

- Successful merges: #31535, #31537, #31542, #31559, #31563, #31582, #31584, #31585, #31589, #31607, #31609, #31610, #31612, #31629, #31635, #31637, #31638
- Failed merges:

1 files changed, 7 insertions, 4 deletions

diff --git a/src/libstd/sys/common/poison.rs b/src/libstd/sys/common/poison.rs
index 2cfa04c843b..d858c002755 100644
--- a/src/libstd/sys/common/poison.rs
+++ b/src/libstd/sys/common/poison.rs
@@ -111,7 +111,7 @@ impl<T> fmt::Display for PoisonError<T> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T: Send + Reflect> Error for PoisonError<T> {
+impl<T: Reflect> Error for PoisonError<T> {
     fn description(&self) -> &str {
         "poisoned lock: another task failed inside"
     }
@@ -158,14 +158,17 @@ impl<T> fmt::Debug for TryLockError<T> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T: Send + Reflect> fmt::Display for TryLockError<T> {
+impl<T> fmt::Display for TryLockError<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        self.description().fmt(f)
+        match *self {
+            TryLockError::Poisoned(..) => "poisoned lock: another task failed inside",
+            TryLockError::WouldBlock => "try_lock failed because the operation would block"
+        }.fmt(f)
     }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T: Send + Reflect> Error for TryLockError<T> {
+impl<T: Reflect> Error for TryLockError<T> {
     fn description(&self) -> &str {
         match *self {
             TryLockError::Poisoned(ref p) => p.description(),