Remove redundant explanatory `note` for type parameters

43 files changed, 6 insertions, 98 deletions

diff --git a/src/librustc_trait_selection/traits/error_reporting/mod.rs b/src/librustc_trait_selection/traits/error_reporting/mod.rs
index 6fb07f5e195..4ade1ce9163 100644
--- a/src/librustc_trait_selection/traits/error_reporting/mod.rs
+++ b/src/librustc_trait_selection/traits/error_reporting/mod.rs
@@ -376,7 +376,12 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                             // If it has a custom `#[rustc_on_unimplemented]`
                             // error message, let's display it as the label!
                             err.span_label(span, s.as_str());
-                            err.help(&explanation);
+                            if !matches!(trait_ref.skip_binder().self_ty().kind, ty::Param(_)) {
+                                // When the self type is a type param We don't need to "the trait
+                                // `std::marker::Sized` is not implemented for `T`" as we will point
+                                // at the type param with a label to suggest constraining it.
+                                err.help(&explanation);
+                            }
                         } else {
                             err.span_label(span, explanation);
                         }
diff --git a/src/test/ui/associated-types/defaults-unsound-62211-1.stderr b/src/test/ui/associated-types/defaults-unsound-62211-1.stderr
index 69c310766c1..2ba854eac46 100644
--- a/src/test/ui/associated-types/defaults-unsound-62211-1.stderr
+++ b/src/test/ui/associated-types/defaults-unsound-62211-1.stderr
@@ -21,7 +21,6 @@ LL | trait UncheckedCopy: Sized {
 LL |     + AddAssign<&'static str>
    |       ^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `Self += &'static str`
    |
-   = help: the trait `std::ops::AddAssign<&'static str>` is not implemented for `Self`
 help: consider further restricting `Self`
    |
 LL | trait UncheckedCopy: Sized + std::ops::AddAssign<&'static str> {
@@ -50,7 +49,6 @@ LL | trait UncheckedCopy: Sized {
 LL |     + Display = Self;
    |       ^^^^^^^ `Self` cannot be formatted with the default formatter
    |
-   = help: the trait `std::fmt::Display` is not implemented for `Self`
    = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
 help: consider further restricting `Self`
    |
@@ -69,7 +67,6 @@ LL |     + Display = Self;
 LL | impl<T> UncheckedCopy for T {}
    |         ^^^^^^^^^^^^^ `T` cannot be formatted with the default formatter
    |
-   = help: the trait `std::fmt::Display` is not implemented for `T`
    = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
 help: consider restricting type parameter `T`
    |
@@ -105,7 +102,6 @@ LL |     + AddAssign<&'static str>
 LL | impl<T> UncheckedCopy for T {}
    |         ^^^^^^^^^^^^^ no implementation for `T += &'static str`
    |
-   = help: the trait `std::ops::AddAssign<&'static str>` is not implemented for `T`
 help: consider restricting type parameter `T`
    |
 LL | impl<T: std::ops::AddAssign<&'static str>> UncheckedCopy for T {}
diff --git a/src/test/ui/associated-types/defaults-unsound-62211-2.stderr b/src/test/ui/associated-types/defaults-unsound-62211-2.stderr
index 84f0ba7529e..d4fd0ca98ee 100644
--- a/src/test/ui/associated-types/defaults-unsound-62211-2.stderr
+++ b/src/test/ui/associated-types/defaults-unsound-62211-2.stderr
@@ -21,7 +21,6 @@ LL | trait UncheckedCopy: Sized {
 LL |     + AddAssign<&'static str>
    |       ^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `Self += &'static str`
    |
-   = help: the trait `std::ops::AddAssign<&'static str>` is not implemented for `Self`
 help: consider further restricting `Self`
    |
 LL | trait UncheckedCopy: Sized + std::ops::AddAssign<&'static str> {
@@ -50,7 +49,6 @@ LL | trait UncheckedCopy: Sized {
 LL |     + Display = Self;
    |       ^^^^^^^ `Self` cannot be formatted with the default formatter
    |
-   = help: the trait `std::fmt::Display` is not implemented for `Self`
    = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
 help: consider further restricting `Self`
    |
@@ -69,7 +67,6 @@ LL |     + Display = Self;
 LL | impl<T> UncheckedCopy for T {}
    |         ^^^^^^^^^^^^^ `T` cannot be formatted with the default formatter
    |
-   = help: the trait `std::fmt::Display` is not implemented for `T`
    = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
 help: consider restricting type parameter `T`
    |
@@ -105,7 +102,6 @@ LL |     + AddAssign<&'static str>
 LL | impl<T> UncheckedCopy for T {}
    |         ^^^^^^^^^^^^^ no implementation for `T += &'static str`
    |
-   = help: the trait `std::ops::AddAssign<&'static str>` is not implemented for `T`
 help: consider restricting type parameter `T`
    |
 LL | impl<T: std::ops::AddAssign<&'static str>> UncheckedCopy for T {}
diff --git a/src/test/ui/associated-types/issue-63593.stderr b/src/test/ui/associated-types/issue-63593.stderr
index c3db950c758..be3b61665b1 100644
--- a/src/test/ui/associated-types/issue-63593.stderr
+++ b/src/test/ui/associated-types/issue-63593.stderr
@@ -6,7 +6,6 @@ LL | trait MyTrait {
 LL |     type This = Self;
    |     ^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Self`
 help: consider further restricting `Self`
    |
 LL | trait MyTrait: std::marker::Sized {
diff --git a/src/test/ui/associated-types/trait-with-supertraits-needing-sized-self.stderr b/src/test/ui/associated-types/trait-with-supertraits-needing-sized-self.stderr
index f2ed2d32bd1..7813d3b6596 100644
--- a/src/test/ui/associated-types/trait-with-supertraits-needing-sized-self.stderr
+++ b/src/test/ui/associated-types/trait-with-supertraits-needing-sized-self.stderr
@@ -9,7 +9,6 @@ LL | trait ArithmeticOps: Add<Output=Self> + Sub<Output=Self> + Mul<Output=Self>
 LL | pub trait Add<Rhs = Self> {
    |               --- required by this bound in `std::ops::Add`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Self`
 help: consider further restricting `Self`
    |
 LL | trait ArithmeticOps: Add<Output=Self> + Sub<Output=Self> + Mul<Output=Self> + Div<Output=Self> + std::marker::Sized {}
diff --git a/src/test/ui/async-await/issue-70818.stderr b/src/test/ui/async-await/issue-70818.stderr
index 5fb772fa10a..2166420070a 100644
--- a/src/test/ui/async-await/issue-70818.stderr
+++ b/src/test/ui/async-await/issue-70818.stderr
@@ -7,7 +7,6 @@ LL |
 LL |     async { (ty, ty1) }
    |     ------------------- this returned value is of type `impl std::future::Future`
    |
-   = help: within `impl std::future::Future`, the trait `std::marker::Send` is not implemented for `U`
 note: captured value is not `Send`
   --> $DIR/issue-70818.rs:6:18
    |
diff --git a/src/test/ui/bad/bad-method-typaram-kind.stderr b/src/test/ui/bad/bad-method-typaram-kind.stderr
index 81fc961e3de..fd3999ae6fb 100644
--- a/src/test/ui/bad/bad-method-typaram-kind.stderr
+++ b/src/test/ui/bad/bad-method-typaram-kind.stderr
@@ -4,7 +4,6 @@ error[E0277]: `T` cannot be sent between threads safely
 LL |     1.bar::<T>();
    |       ^^^ `T` cannot be sent between threads safely
    |
-   = help: the trait `std::marker::Send` is not implemented for `T`
 help: consider further restricting this bound
    |
 LL | fn foo<T:'static + std::marker::Send>() {
diff --git a/src/test/ui/bound-suggestions.stderr b/src/test/ui/bound-suggestions.stderr
index b9bc503f530..623252a8c11 100644
--- a/src/test/ui/bound-suggestions.stderr
+++ b/src/test/ui/bound-suggestions.stderr
@@ -4,7 +4,6 @@ error[E0277]: `impl Sized` doesn't implement `std::fmt::Debug`
 LL |     println!("{:?}", t);
    |                      ^ `impl Sized` cannot be formatted using `{:?}` because it doesn't implement `std::fmt::Debug`
    |
-   = help: the trait `std::fmt::Debug` is not implemented for `impl Sized`
    = note: required by `std::fmt::Debug::fmt`
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider further restricting this bound
@@ -18,7 +17,6 @@ error[E0277]: `T` doesn't implement `std::fmt::Debug`
 LL |     println!("{:?}", t);
    |                      ^ `T` cannot be formatted using `{:?}` because it doesn't implement `std::fmt::Debug`
    |
-   = help: the trait `std::fmt::Debug` is not implemented for `T`
    = note: required by `std::fmt::Debug::fmt`
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider restricting type parameter `T`
@@ -32,7 +30,6 @@ error[E0277]: `T` doesn't implement `std::fmt::Debug`
 LL |     println!("{:?}", t);
    |                      ^ `T` cannot be formatted using `{:?}` because it doesn't implement `std::fmt::Debug`
    |
-   = help: the trait `std::fmt::Debug` is not implemented for `T`
    = note: required by `std::fmt::Debug::fmt`
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider further restricting this bound
@@ -46,7 +43,6 @@ error[E0277]: `Y` doesn't implement `std::fmt::Debug`
 LL |     println!("{:?} {:?}", x, y);
    |                              ^ `Y` cannot be formatted using `{:?}` because it doesn't implement `std::fmt::Debug`
    |
-   = help: the trait `std::fmt::Debug` is not implemented for `Y`
    = note: required by `std::fmt::Debug::fmt`
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider further restricting type parameter `Y`
@@ -60,7 +56,6 @@ error[E0277]: `X` doesn't implement `std::fmt::Debug`
 LL |     println!("{:?}", x);
    |                      ^ `X` cannot be formatted using `{:?}` because it doesn't implement `std::fmt::Debug`
    |
-   = help: the trait `std::fmt::Debug` is not implemented for `X`
    = note: required by `std::fmt::Debug::fmt`
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider further restricting this bound
@@ -74,7 +69,6 @@ error[E0277]: `X` doesn't implement `std::fmt::Debug`
 LL |     println!("{:?}", x);
    |                      ^ `X` cannot be formatted using `{:?}` because it doesn't implement `std::fmt::Debug`
    |
-   = help: the trait `std::fmt::Debug` is not implemented for `X`
    = note: required by `std::fmt::Debug::fmt`
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider further restricting type parameter `X`
diff --git a/src/test/ui/builtin-superkinds/builtin-superkinds-double-superkind.stderr b/src/test/ui/builtin-superkinds/builtin-superkinds-double-superkind.stderr
index 4e7b513629d..7ff986ec381 100644
--- a/src/test/ui/builtin-superkinds/builtin-superkinds-double-superkind.stderr
+++ b/src/test/ui/builtin-superkinds/builtin-superkinds-double-superkind.stderr
@@ -7,7 +7,6 @@ LL |
 LL | impl <T: Sync+'static> Foo for (T,) { }
    |                        ^^^ `T` cannot be sent between threads safely
    |
-   = help: within `(T,)`, the trait `std::marker::Send` is not implemented for `T`
    = note: required because it appears within the type `(T,)`
 help: consider further restricting this bound
    |
@@ -23,7 +22,6 @@ LL | trait Foo : Send+Sync { }
 LL | impl <T: Send> Foo for (T,T) { }
    |                ^^^ `T` cannot be shared between threads safely
    |
-   = help: within `(T, T)`, the trait `std::marker::Sync` is not implemented for `T`
    = note: required because it appears within the type `(T, T)`
 help: consider further restricting this bound
    |
diff --git a/src/test/ui/builtin-superkinds/builtin-superkinds-in-metadata.stderr b/src/test/ui/builtin-superkinds/builtin-superkinds-in-metadata.stderr
index 3fb1af3a67c..9ee045edfe5 100644
--- a/src/test/ui/builtin-superkinds/builtin-superkinds-in-metadata.stderr
+++ b/src/test/ui/builtin-superkinds/builtin-superkinds-in-metadata.stderr
@@ -9,7 +9,6 @@ LL | impl <T:Sync+'static> RequiresRequiresShareAndSend for X<T> { }
 LL | pub trait RequiresRequiresShareAndSend : RequiresShare + Send { }
    |                                                          ---- required by this bound in `trait_superkinds_in_metadata::RequiresRequiresShareAndSend`
    |
-   = help: within `X<T>`, the trait `std::marker::Send` is not implemented for `T`
    = note: required because it appears within the type `X<T>`
 help: consider further restricting this bound
    |
diff --git a/src/test/ui/builtin-superkinds/builtin-superkinds-typaram-not-send.stderr b/src/test/ui/builtin-superkinds/builtin-superkinds-typaram-not-send.stderr
index 9c5073a1e49..ad80b3fa8d1 100644
--- a/src/test/ui/builtin-superkinds/builtin-superkinds-typaram-not-send.stderr
+++ b/src/test/ui/builtin-superkinds/builtin-superkinds-typaram-not-send.stderr
@@ -7,7 +7,6 @@ LL |
 LL | impl <T: Sync+'static> Foo for T { }
    |                        ^^^ `T` cannot be sent between threads safely
    |
-   = help: the trait `std::marker::Send` is not implemented for `T`
 help: consider further restricting this bound
    |
 LL | impl <T: Sync+'static + std::marker::Send> Foo for T { }
diff --git a/src/test/ui/closures/closure-bounds-cant-promote-superkind-in-struct.stderr b/src/test/ui/closures/closure-bounds-cant-promote-superkind-in-struct.stderr
index ffd70fac6b1..273eae99553 100644
--- a/src/test/ui/closures/closure-bounds-cant-promote-superkind-in-struct.stderr
+++ b/src/test/ui/closures/closure-bounds-cant-promote-superkind-in-struct.stderr
@@ -7,7 +7,6 @@ LL | struct X<F> where F: FnOnce() + 'static + Send {
 LL | fn foo<F>(blk: F) -> X<F> where F: FnOnce() + 'static {
    |                      ^^^^ `F` cannot be sent between threads safely
    |
-   = help: the trait `std::marker::Send` is not implemented for `F`
 help: consider further restricting this bound
    |
 LL | fn foo<F>(blk: F) -> X<F> where F: FnOnce() + 'static + std::marker::Send {
diff --git a/src/test/ui/closures/closure-bounds-subtype.stderr b/src/test/ui/closures/closure-bounds-subtype.stderr
index 691864c9e1d..7df29d5a098 100644
--- a/src/test/ui/closures/closure-bounds-subtype.stderr
+++ b/src/test/ui/closures/closure-bounds-subtype.stderr
@@ -7,7 +7,6 @@ LL | fn take_const_owned<F>(_: F) where F: FnOnce() + Sync + Send {
 LL |     take_const_owned(f);
    |                      ^ `F` cannot be shared between threads safely
    |
-   = help: the trait `std::marker::Sync` is not implemented for `F`
 help: consider further restricting this bound
    |
 LL | fn give_owned<F>(f: F) where F: FnOnce() + Send + std::marker::Sync {
diff --git a/src/test/ui/dst/dst-object-from-unsized-type.stderr b/src/test/ui/dst/dst-object-from-unsized-type.stderr
index d6e9aaab7cf..da8ead885c8 100644
--- a/src/test/ui/dst/dst-object-from-unsized-type.stderr
+++ b/src/test/ui/dst/dst-object-from-unsized-type.stderr
@@ -6,7 +6,6 @@ LL | fn test1<T: ?Sized + Foo>(t: &T) {
 LL |     let u: &dyn Foo = t;
    |                       ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `T`
    = note: required for the cast to the object type `dyn Foo`
 
 error[E0277]: the size for values of type `T` cannot be known at compilation time
@@ -17,7 +16,6 @@ LL | fn test2<T: ?Sized + Foo>(t: &T) {
 LL |     let v: &dyn Foo = t as &dyn Foo;
    |                       ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `T`
    = note: required for the cast to the object type `dyn Foo`
 
 error[E0277]: the size for values of type `str` cannot be known at compilation time
diff --git a/src/test/ui/generic-associated-types/issue-68642-broken-llvm-ir.stderr b/src/test/ui/generic-associated-types/issue-68642-broken-llvm-ir.stderr
index 89cc5dfd060..2fab7ffb660 100644
--- a/src/test/ui/generic-associated-types/issue-68642-broken-llvm-ir.stderr
+++ b/src/test/ui/generic-associated-types/issue-68642-broken-llvm-ir.stderr
@@ -16,7 +16,6 @@ LL |     type F<'a>: Fn() -> u32;
 LL |     type F<'a> = Self;
    |     ^^^^^^^^^^^^^^^^^^ expected an `Fn<()>` closure, found `T`
    |
-   = help: the trait `std::ops::Fn<()>` is not implemented for `T`
    = note: wrap the `T` in a closure with no arguments: `|| { /* code */ }
 help: consider restricting type parameter `T`
    |
diff --git a/src/test/ui/generic-associated-types/issue-68643-broken-mir.stderr b/src/test/ui/generic-associated-types/issue-68643-broken-mir.stderr
index efd3287853f..186e142138b 100644
--- a/src/test/ui/generic-associated-types/issue-68643-broken-mir.stderr
+++ b/src/test/ui/generic-associated-types/issue-68643-broken-mir.stderr
@@ -16,7 +16,6 @@ LL |     type F<'a>: Fn() -> u32;
 LL |     type F<'a> = Self;
    |     ^^^^^^^^^^^^^^^^^^ expected an `Fn<()>` closure, found `T`
    |
-   = help: the trait `std::ops::Fn<()>` is not implemented for `T`
    = note: wrap the `T` in a closure with no arguments: `|| { /* code */ }
 help: consider restricting type parameter `T`
    |
diff --git a/src/test/ui/generic-associated-types/issue-68644-codegen-selection.stderr b/src/test/ui/generic-associated-types/issue-68644-codegen-selection.stderr
index 5da924a512f..d16bdcbbb6b 100644
--- a/src/test/ui/generic-associated-types/issue-68644-codegen-selection.stderr
+++ b/src/test/ui/generic-associated-types/issue-68644-codegen-selection.stderr
@@ -16,7 +16,6 @@ LL |     type F<'a>: Fn() -> u32;
 LL |     type F<'a> = Self;
    |     ^^^^^^^^^^^^^^^^^^ expected an `Fn<()>` closure, found `T`
    |
-   = help: the trait `std::ops::Fn<()>` is not implemented for `T`
    = note: wrap the `T` in a closure with no arguments: `|| { /* code */ }
 help: consider restricting type parameter `T`
    |
diff --git a/src/test/ui/generic-associated-types/issue-68645-codegen-fulfillment.stderr b/src/test/ui/generic-associated-types/issue-68645-codegen-fulfillment.stderr
index 12d84ab6a36..72c42917c83 100644
--- a/src/test/ui/generic-associated-types/issue-68645-codegen-fulfillment.stderr
+++ b/src/test/ui/generic-associated-types/issue-68645-codegen-fulfillment.stderr
@@ -16,7 +16,6 @@ LL |     type F<'a>: Fn() -> u32;
 LL |     type F<'a> = Self;
    |     ^^^^^^^^^^^^^^^^^^ expected an `Fn<()>` closure, found `T`
    |
-   = help: the trait `std::ops::Fn<()>` is not implemented for `T`
    = note: wrap the `T` in a closure with no arguments: `|| { /* code */ }
 help: consider restricting type parameter `T`
    |
diff --git a/src/test/ui/issues/issue-20005.stderr b/src/test/ui/issues/issue-20005.stderr
index 7bd25783444..cbaa7507244 100644
--- a/src/test/ui/issues/issue-20005.stderr
+++ b/src/test/ui/issues/issue-20005.stderr
@@ -7,7 +7,6 @@ LL | trait From<Src> {
 LL |     ) -> <Dst as From<Self>>::Result where Dst: From<Self> {
    |                                                 ^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Self`
 help: consider further restricting `Self`
    |
 LL |     ) -> <Dst as From<Self>>::Result where Dst: From<Self>, Self: std::marker::Sized {
diff --git a/src/test/ui/issues/issue-27060-2.stderr b/src/test/ui/issues/issue-27060-2.stderr
index 881fae19423..96696fabd93 100644
--- a/src/test/ui/issues/issue-27060-2.stderr
+++ b/src/test/ui/issues/issue-27060-2.stderr
@@ -6,7 +6,6 @@ LL | pub struct Bad<T: ?Sized> {
 LL |     data: T,
    |           ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `T`
    = note: the last field of a packed struct may only have a dynamically sized type if it does not need drop to be run
    = help: change the field's type to have a statically known size
 help: borrowed types always have a statically known size
diff --git a/src/test/ui/issues/issue-27078.stderr b/src/test/ui/issues/issue-27078.stderr
index 4b031d26ad5..de1810e99aa 100644
--- a/src/test/ui/issues/issue-27078.stderr
+++ b/src/test/ui/issues/issue-27078.stderr
@@ -4,7 +4,6 @@ error[E0277]: the size for values of type `Self` cannot be known at compilation
 LL |     fn foo(self) -> &'static i32 {
    |            ^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Self`
    = help: unsized locals are gated as an unstable feature
 help: consider further restricting `Self`
    |
diff --git a/src/test/ui/kindck/kindck-impl-type-params.nll.stderr b/src/test/ui/kindck/kindck-impl-type-params.nll.stderr
index a2f70a8c240..eb400cf0615 100644
--- a/src/test/ui/kindck/kindck-impl-type-params.nll.stderr
+++ b/src/test/ui/kindck/kindck-impl-type-params.nll.stderr
@@ -4,7 +4,6 @@ error[E0277]: `T` cannot be sent between threads safely
 LL |     let a = &t as &dyn Gettable<T>;
    |             ^^ `T` cannot be sent between threads safely
    |
-   = help: the trait `std::marker::Send` is not implemented for `T`
    = note: required because of the requirements on the impl of `Gettable<T>` for `S<T>`
    = note: required for the cast to the object type `dyn Gettable<T>`
 help: consider restricting type parameter `T`
@@ -31,7 +30,6 @@ error[E0277]: `T` cannot be sent between threads safely
 LL |     let a: &dyn Gettable<T> = &t;
    |                               ^^ `T` cannot be sent between threads safely
    |
-   = help: the trait `std::marker::Send` is not implemented for `T`
    = note: required because of the requirements on the impl of `Gettable<T>` for `S<T>`
    = note: required for the cast to the object type `dyn Gettable<T>`
 help: consider restricting type parameter `T`
diff --git a/src/test/ui/kindck/kindck-impl-type-params.stderr b/src/test/ui/kindck/kindck-impl-type-params.stderr
index cc98f1d9f34..ab9dfc9b8a7 100644
--- a/src/test/ui/kindck/kindck-impl-type-params.stderr
+++ b/src/test/ui/kindck/kindck-impl-type-params.stderr
@@ -4,7 +4,6 @@ error[E0277]: `T` cannot be sent between threads safely
 LL |     let a = &t as &dyn Gettable<T>;
    |             ^^ `T` cannot be sent between threads safely
    |
-   = help: the trait `std::marker::Send` is not implemented for `T`
    = note: required because of the requirements on the impl of `Gettable<T>` for `S<T>`
    = note: required for the cast to the object type `dyn Gettable<T>`
 help: consider restricting type parameter `T`
@@ -31,7 +30,6 @@ error[E0277]: `T` cannot be sent between threads safely
 LL |     let a: &dyn Gettable<T> = &t;
    |                               ^^ `T` cannot be sent between threads safely
    |
-   = help: the trait `std::marker::Send` is not implemented for `T`
    = note: required because of the requirements on the impl of `Gettable<T>` for `S<T>`
    = note: required for the cast to the object type `dyn Gettable<T>`
 help: consider restricting type parameter `T`
diff --git a/src/test/ui/lazy_normalization_consts/feature-gate-lazy_normalization_consts.stderr b/src/test/ui/lazy_normalization_consts/feature-gate-lazy_normalization_consts.stderr
index 97c74178398..98bf9923823 100644
--- a/src/test/ui/lazy_normalization_consts/feature-gate-lazy_normalization_consts.stderr
+++ b/src/test/ui/lazy_normalization_consts/feature-gate-lazy_normalization_consts.stderr
@@ -9,7 +9,6 @@ LL | fn test<T>() {
 LL |     let _: [u8; sof::<T>()];
    |                       ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `T`
 help: consider relaxing the implicit `Sized` restriction
    |
 LL | pub const fn sof<T: ?Sized>() -> usize {
diff --git a/src/test/ui/phantom-oibit.stderr b/src/test/ui/phantom-oibit.stderr
index fd0307f15c7..e143747d637 100644
--- a/src/test/ui/phantom-oibit.stderr
+++ b/src/test/ui/phantom-oibit.stderr
@@ -7,7 +7,6 @@ LL | fn is_zen<T: Zen>(_: T) {}
 LL |     is_zen(x)
    |            ^ `T` cannot be shared between threads safely
    |
-   = help: the trait `std::marker::Sync` is not implemented for `T`
    = note: required because of the requirements on the impl of `Zen` for `&T`
    = note: required because it appears within the type `std::marker::PhantomData<&T>`
    = note: required because it appears within the type `Guard<'_, T>`
@@ -25,7 +24,6 @@ LL | fn is_zen<T: Zen>(_: T) {}
 LL |     is_zen(x)
    |            ^ `T` cannot be shared between threads safely
    |
-   = help: the trait `std::marker::Sync` is not implemented for `T`
    = note: required because of the requirements on the impl of `Zen` for `&T`
    = note: required because it appears within the type `std::marker::PhantomData<&T>`
    = note: required because it appears within the type `Guard<'_, T>`
diff --git a/src/test/ui/specialization/deafult-generic-associated-type-bound.stderr b/src/test/ui/specialization/deafult-generic-associated-type-bound.stderr
index 7f3c49e753f..3da8725d88a 100644
--- a/src/test/ui/specialization/deafult-generic-associated-type-bound.stderr
+++ b/src/test/ui/specialization/deafult-generic-associated-type-bound.stderr
@@ -24,7 +24,6 @@ LL |     type U<'a>: PartialEq<&'a Self>;
 LL |     default type U<'a> = &'a T;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `T == T`
    |
-   = help: the trait `std::cmp::PartialEq` is not implemented for `T`
    = note: required because of the requirements on the impl of `std::cmp::PartialEq` for `&'a T`
 help: consider further restricting this bound
    |
diff --git a/src/test/ui/suggestions/adt-param-with-implicit-sized-bound.stderr b/src/test/ui/suggestions/adt-param-with-implicit-sized-bound.stderr
index 0b08b4a16a6..f4c0d0f96c4 100644
--- a/src/test/ui/suggestions/adt-param-with-implicit-sized-bound.stderr
+++ b/src/test/ui/suggestions/adt-param-with-implicit-sized-bound.stderr
@@ -9,7 +9,6 @@ LL | struct Struct5<T: ?Sized>{
 LL |     _t: X<T>,
    |         ^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `T`
 help: you could relax the implicit `Sized` bound on `T` if it were used through indirection like `&T` or `Box<T>`
   --> $DIR/adt-param-with-implicit-sized-bound.rs:18:10
    |
@@ -27,7 +26,6 @@ LL |     fn func1() -> Struct1<Self>;
 LL | struct Struct1<T>{
    |                - required by this bound in `Struct1`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Self`
 help: consider further restricting `Self`
    |
 LL |     fn func1() -> Struct1<Self> where Self: std::marker::Sized;
@@ -46,7 +44,6 @@ LL |     fn func2<'a>() -> Struct2<'a, Self>;
 LL | struct Struct2<'a, T>{
    |                    - required by this bound in `Struct2`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Self`
 help: consider further restricting `Self`
    |
 LL |     fn func2<'a>() -> Struct2<'a, Self> where Self: std::marker::Sized;
@@ -65,7 +62,6 @@ LL |     fn func3() -> Struct3<Self>;
 LL | struct Struct3<T>{
    |                - required by this bound in `Struct3`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Self`
 help: you could relax the implicit `Sized` bound on `T` if it were used through indirection like `&T` or `Box<T>`
   --> $DIR/adt-param-with-implicit-sized-bound.rs:14:16
    |
@@ -87,7 +83,6 @@ LL |     fn func4() -> Struct4<Self>;
 LL | struct Struct4<T>{
    |                - required by this bound in `Struct4`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Self`
 help: consider further restricting `Self`
    |
 LL |     fn func4() -> Struct4<Self> where Self: std::marker::Sized;
diff --git a/src/test/ui/suggestions/restrict-type-argument.stderr b/src/test/ui/suggestions/restrict-type-argument.stderr
index 0c52778b0d8..33af13d943f 100644
--- a/src/test/ui/suggestions/restrict-type-argument.stderr
+++ b/src/test/ui/suggestions/restrict-type-argument.stderr
@@ -7,7 +7,6 @@ LL | fn is_send<T: Send>(val: T) {}
 LL |     is_send(val);
    |             ^^^ `impl Sync` cannot be sent between threads safely
    |
-   = help: the trait `std::marker::Send` is not implemented for `impl Sync`
 help: consider further restricting this bound
    |
 LL | fn use_impl_sync(val: impl Sync + std::marker::Send) {
@@ -22,7 +21,6 @@ LL | fn is_send<T: Send>(val: T) {}
 LL |     is_send(val);
    |             ^^^ `S` cannot be sent between threads safely
    |
-   = help: the trait `std::marker::Send` is not implemented for `S`
 help: consider further restricting this bound
    |
 LL | fn use_where<S>(val: S) where S: Sync + std::marker::Send {
@@ -37,7 +35,6 @@ LL | fn is_send<T: Send>(val: T) {}
 LL |     is_send(val);
    |             ^^^ `S` cannot be sent between threads safely
    |
-   = help: the trait `std::marker::Send` is not implemented for `S`
 help: consider further restricting this bound
    |
 LL | fn use_bound<S: Sync + std::marker::Send>(val: S) {
@@ -52,7 +49,6 @@ LL | fn is_send<T: Send>(val: T) {}
 LL |     is_send(val);
    |             ^^^ `S` cannot be sent between threads safely
    |
-   = help: the trait `std::marker::Send` is not implemented for `S`
 help: consider further restricting this bound
    |
 LL |     Sync + std::marker::Send
@@ -67,7 +63,6 @@ LL | fn is_send<T: Send>(val: T) {}
 LL |     is_send(val);
    |             ^^^ `S` cannot be sent between threads safely
    |
-   = help: the trait `std::marker::Send` is not implemented for `S`
 help: consider further restricting this bound
    |
 LL | fn use_bound_and_where<S: Sync>(val: S) where S: std::fmt::Debug + std::marker::Send {
@@ -82,7 +77,6 @@ LL | fn is_send<T: Send>(val: T) {}
 LL |     is_send(val);
    |             ^^^ `S` cannot be sent between threads safely
    |
-   = help: the trait `std::marker::Send` is not implemented for `S`
 help: consider restricting type parameter `S`
    |
 LL | fn use_unbound<S: std::marker::Send>(val: S) {
diff --git a/src/test/ui/traits/trait-suggest-where-clause.stderr b/src/test/ui/traits/trait-suggest-where-clause.stderr
index b8069f9ddb0..86a313baa5c 100644
--- a/src/test/ui/traits/trait-suggest-where-clause.stderr
+++ b/src/test/ui/traits/trait-suggest-where-clause.stderr
@@ -11,8 +11,6 @@ LL |     mem::size_of::<U>();
    |
 LL | pub const fn size_of<T>() -> usize {
    |                      - required by this bound in `std::mem::size_of`
-   |
-   = help: the trait `std::marker::Sized` is not implemented for `U`
 
 error[E0277]: the size for values of type `U` cannot be known at compilation time
   --> $DIR/trait-suggest-where-clause.rs:10:5
@@ -28,7 +26,6 @@ LL |     mem::size_of::<Misc<U>>();
 LL | pub const fn size_of<T>() -> usize {
    |                      - required by this bound in `std::mem::size_of`
    |
-   = help: within `Misc<U>`, the trait `std::marker::Sized` is not implemented for `U`
    = note: required because it appears within the type `Misc<U>`
 
 error[E0277]: the trait bound `u64: std::convert::From<T>` is not satisfied
diff --git a/src/test/ui/type-alias-impl-trait/generic_underconstrained2.stderr b/src/test/ui/type-alias-impl-trait/generic_underconstrained2.stderr
index 247d68ef2a1..28e30cbdd9d 100644
--- a/src/test/ui/type-alias-impl-trait/generic_underconstrained2.stderr
+++ b/src/test/ui/type-alias-impl-trait/generic_underconstrained2.stderr
@@ -19,7 +19,6 @@ LL | type Underconstrained<T: std::fmt::Debug> = impl 'static;
 LL |     5u32
    |     ---- this returned value is of type `u32`
    |
-   = help: the trait `std::fmt::Debug` is not implemented for `U`
    = note: the return type of a function must have a statically known size
 help: consider restricting type parameter `U`
    |
@@ -35,7 +34,6 @@ LL | type Underconstrained2<T: std::fmt::Debug> = impl 'static;
 LL |     5u32
    |     ---- this returned value is of type `u32`
    |
-   = help: the trait `std::fmt::Debug` is not implemented for `V`
    = note: the return type of a function must have a statically known size
 help: consider restricting type parameter `V`
    |
diff --git a/src/test/ui/typeck/typeck-default-trait-impl-send-param.stderr b/src/test/ui/typeck/typeck-default-trait-impl-send-param.stderr
index 9cba3578449..7398b48a238 100644
--- a/src/test/ui/typeck/typeck-default-trait-impl-send-param.stderr
+++ b/src/test/ui/typeck/typeck-default-trait-impl-send-param.stderr
@@ -7,7 +7,6 @@ LL |     is_send::<T>()
 LL | fn is_send<T:Send>() {
    |              ---- required by this bound in `is_send`
    |
-   = help: the trait `std::marker::Send` is not implemented for `T`
 help: consider restricting type parameter `T`
    |
 LL | fn foo<T: std::marker::Send>() {
diff --git a/src/test/ui/union/union-sized-field.stderr b/src/test/ui/union/union-sized-field.stderr
index eb169987ccd..d7224e46add 100644
--- a/src/test/ui/union/union-sized-field.stderr
+++ b/src/test/ui/union/union-sized-field.stderr
@@ -6,7 +6,6 @@ LL | union Foo<T: ?Sized> {
 LL |     value: T,
    |            ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `T`
    = note: no field of a union may have a dynamically sized type
    = help: change the field's type to have a statically known size
 help: borrowed types always have a statically known size
@@ -26,7 +25,6 @@ LL | struct Foo2<T: ?Sized> {
 LL |     value: T,
    |            ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `T`
    = note: only the last field of a struct may have a dynamically sized type
    = help: change the field's type to have a statically known size
 help: borrowed types always have a statically known size
@@ -46,7 +44,6 @@ LL | enum Foo3<T: ?Sized> {
 LL |     Value(T),
    |           ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `T`
    = note: no field of an enum variant may have a dynamically sized type
    = help: change the field's type to have a statically known size
 help: borrowed types always have a statically known size
diff --git a/src/test/ui/unsized/unsized-bare-typaram.stderr b/src/test/ui/unsized/unsized-bare-typaram.stderr
index 998cd7a527c..19978ae24ca 100644
--- a/src/test/ui/unsized/unsized-bare-typaram.stderr
+++ b/src/test/ui/unsized/unsized-bare-typaram.stderr
@@ -7,8 +7,6 @@ LL | fn foo<T: ?Sized>() { bar::<T>() }
    |        -                    ^ doesn't have a size known at compile-time
    |        |
    |        this type parameter needs to be `std::marker::Sized`
-   |
-   = help: the trait `std::marker::Sized` is not implemented for `T`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/unsized/unsized-enum.stderr b/src/test/ui/unsized/unsized-enum.stderr
index cb06e707dca..fdfdb9b4e2a 100644
--- a/src/test/ui/unsized/unsized-enum.stderr
+++ b/src/test/ui/unsized/unsized-enum.stderr
@@ -9,7 +9,6 @@ LL | fn foo2<T: ?Sized>() { not_sized::<Foo<T>>() }
    |         |
    |         this type parameter needs to be `std::marker::Sized`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `T`
 help: you could relax the implicit `Sized` bound on `U` if it were used through indirection like `&U` or `Box<U>`
   --> $DIR/unsized-enum.rs:4:10
    |
diff --git a/src/test/ui/unsized/unsized-enum2.stderr b/src/test/ui/unsized/unsized-enum2.stderr
index 82f395740d5..742abc39209 100644
--- a/src/test/ui/unsized/unsized-enum2.stderr
+++ b/src/test/ui/unsized/unsized-enum2.stderr
@@ -7,7 +7,6 @@ LL |     // parameter
 LL |     VA(W),
    |        ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `W`
    = note: no field of an enum variant may have a dynamically sized type
    = help: change the field's type to have a statically known size
 help: borrowed types always have a statically known size
@@ -28,7 +27,6 @@ LL | enum E<W: ?Sized, X: ?Sized, Y: ?Sized, Z: ?Sized> {
 LL |     VB{x: X},
    |           ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: no field of an enum variant may have a dynamically sized type
    = help: change the field's type to have a statically known size
 help: borrowed types always have a statically known size
@@ -49,7 +47,6 @@ LL | enum E<W: ?Sized, X: ?Sized, Y: ?Sized, Z: ?Sized> {
 LL |     VC(isize, Y),
    |               ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Y`
    = note: no field of an enum variant may have a dynamically sized type
    = help: change the field's type to have a statically known size
 help: borrowed types always have a statically known size
@@ -70,7 +67,6 @@ LL | enum E<W: ?Sized, X: ?Sized, Y: ?Sized, Z: ?Sized> {
 LL |     VD{u: isize, x: Z},
    |                     ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Z`
    = note: no field of an enum variant may have a dynamically sized type
    = help: change the field's type to have a statically known size
 help: borrowed types always have a statically known size
diff --git a/src/test/ui/unsized/unsized-inherent-impl-self-type.stderr b/src/test/ui/unsized/unsized-inherent-impl-self-type.stderr
index 0d08f70c558..50b54593f3a 100644
--- a/src/test/ui/unsized/unsized-inherent-impl-self-type.stderr
+++ b/src/test/ui/unsized/unsized-inherent-impl-self-type.stderr
@@ -9,7 +9,6 @@ LL | impl<X: ?Sized> S5<X> {
    |      |
    |      this type parameter needs to be `std::marker::Sized`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
 help: you could relax the implicit `Sized` bound on `Y` if it were used through indirection like `&Y` or `Box<Y>`
   --> $DIR/unsized-inherent-impl-self-type.rs:5:11
    |
diff --git a/src/test/ui/unsized/unsized-struct.stderr b/src/test/ui/unsized/unsized-struct.stderr
index d796fcd1a6b..0c8529bf1a9 100644
--- a/src/test/ui/unsized/unsized-struct.stderr
+++ b/src/test/ui/unsized/unsized-struct.stderr
@@ -9,7 +9,6 @@ LL | fn foo2<T: ?Sized>() { not_sized::<Foo<T>>() }
    |         |
    |         this type parameter needs to be `std::marker::Sized`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `T`
 help: you could relax the implicit `Sized` bound on `T` if it were used through indirection like `&T` or `Box<T>`
   --> $DIR/unsized-struct.rs:4:12
    |
@@ -29,7 +28,6 @@ LL | fn bar2<T: ?Sized>() { is_sized::<Bar<T>>() }
    |         |
    |         this type parameter needs to be `std::marker::Sized`
    |
-   = help: within `Bar<T>`, the trait `std::marker::Sized` is not implemented for `T`
    = note: required because it appears within the type `Bar<T>`
 
 error: aborting due to 2 previous errors
diff --git a/src/test/ui/unsized/unsized-trait-impl-self-type.stderr b/src/test/ui/unsized/unsized-trait-impl-self-type.stderr
index 623c83c4d6f..4514208a90d 100644
--- a/src/test/ui/unsized/unsized-trait-impl-self-type.stderr
+++ b/src/test/ui/unsized/unsized-trait-impl-self-type.stderr
@@ -9,7 +9,6 @@ LL | impl<X: ?Sized> T3<X> for S5<X> {
    |      |
    |      this type parameter needs to be `std::marker::Sized`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
 help: you could relax the implicit `Sized` bound on `Y` if it were used through indirection like `&Y` or `Box<Y>`
   --> $DIR/unsized-trait-impl-self-type.rs:8:11
    |
diff --git a/src/test/ui/unsized/unsized-trait-impl-trait-arg.stderr b/src/test/ui/unsized/unsized-trait-impl-trait-arg.stderr
index 1dc9e313d91..f48d4ef9f14 100644
--- a/src/test/ui/unsized/unsized-trait-impl-trait-arg.stderr
+++ b/src/test/ui/unsized/unsized-trait-impl-trait-arg.stderr
@@ -9,7 +9,6 @@ LL | impl<X: ?Sized> T2<X> for S4<X> {
    |      |
    |      this type parameter needs to be `std::marker::Sized`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
 help: consider relaxing the implicit `Sized` restriction
    |
 LL | trait T2<Z: ?Sized> {
diff --git a/src/test/ui/unsized3.stderr b/src/test/ui/unsized3.stderr
index d5c79c71a23..ddddae4eaba 100644
--- a/src/test/ui/unsized3.stderr
+++ b/src/test/ui/unsized3.stderr
@@ -9,7 +9,6 @@ LL |     f2::<X>(x);
 LL | fn f2<X>(x: &X) {
    |       - required by this bound in `f2`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
 help: consider relaxing the implicit `Sized` restriction
    |
 LL | fn f2<X: ?Sized>(x: &X) {
@@ -26,7 +25,6 @@ LL |     f4::<X>(x);
 LL | fn f4<X: T>(x: &X) {
    |       - required by this bound in `f4`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
 help: consider relaxing the implicit `Sized` restriction
    |
 LL | fn f4<X: T + ?Sized>(x: &X) {
@@ -43,7 +41,6 @@ LL | fn f8<X: ?Sized>(x1: &S<X>, x2: &S<X>) {
 LL |     f5(x1);
    |        ^^ doesn't have a size known at compile-time
    |
-   = help: within `S<X>`, the trait `std::marker::Sized` is not implemented for `X`
    = note: required because it appears within the type `S<X>`
 help: consider relaxing the implicit `Sized` restriction
    |
@@ -58,7 +55,6 @@ LL | fn f9<X: ?Sized>(x1: Box<S<X>>) {
 LL |     f5(&(*x1, 34));
    |        ^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `S<X>`, the trait `std::marker::Sized` is not implemented for `X`
    = note: required because it appears within the type `S<X>`
    = note: only the last element of a tuple may have a dynamically sized type
 
@@ -70,7 +66,6 @@ LL | fn f10<X: ?Sized>(x1: Box<S<X>>) {
 LL |     f5(&(32, *x1));
    |         ^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `({integer}, S<X>)`, the trait `std::marker::Sized` is not implemented for `X`
    = note: required because it appears within the type `S<X>`
    = note: required because it appears within the type `({integer}, S<X>)`
    = note: tuples must have a statically known size to be initialized
@@ -86,7 +81,6 @@ LL | fn f10<X: ?Sized>(x1: Box<S<X>>) {
 LL |     f5(&(32, *x1));
    |        ^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `({integer}, S<X>)`, the trait `std::marker::Sized` is not implemented for `X`
    = note: required because it appears within the type `S<X>`
    = note: required because it appears within the type `({integer}, S<X>)`
 help: consider relaxing the implicit `Sized` restriction
diff --git a/src/test/ui/unsized5.stderr b/src/test/ui/unsized5.stderr
index 9bdcc0399b8..80cf4baeab7 100644
--- a/src/test/ui/unsized5.stderr
+++ b/src/test/ui/unsized5.stderr
@@ -6,7 +6,6 @@ LL | struct S1<X: ?Sized> {
 LL |     f1: X,
    |         ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: only the last field of a struct may have a dynamically sized type
    = help: change the field's type to have a statically known size
 help: borrowed types always have a statically known size
@@ -27,7 +26,6 @@ LL |     f: isize,
 LL |     g: X,
    |        ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: only the last field of a struct may have a dynamically sized type
    = help: change the field's type to have a statically known size
 help: borrowed types always have a statically known size
@@ -83,7 +81,6 @@ LL | enum E<X: ?Sized> {
 LL |     V1(X, isize),
    |        ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: no field of an enum variant may have a dynamically sized type
    = help: change the field's type to have a statically known size
 help: borrowed types always have a statically known size
@@ -103,7 +100,6 @@ LL | enum F<X: ?Sized> {
 LL |     V2{f1: X, f: isize},
    |            ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: no field of an enum variant may have a dynamically sized type
    = help: change the field's type to have a statically known size
 help: borrowed types always have a statically known size
diff --git a/src/test/ui/unsized6.stderr b/src/test/ui/unsized6.stderr
index 82f1e87008d..f045bfe2444 100644
--- a/src/test/ui/unsized6.stderr
+++ b/src/test/ui/unsized6.stderr
@@ -7,7 +7,6 @@ LL | fn f1<W: ?Sized, X: ?Sized, Y: ?Sized, Z: ?Sized>(x: &X) {
 LL |     let y: Y;
    |         ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Y`
    = note: all local variables must have a statically known size
    = help: unsized locals are gated as an unstable feature
 
@@ -20,7 +19,6 @@ LL |     let _: W; // <-- this is OK, no bindings created, no initializer.
 LL |     let _: (isize, (X, isize));
    |            ^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: only the last element of a tuple may have a dynamically sized type
 
 error[E0277]: the size for values of type `Z` cannot be known at compilation time
@@ -32,7 +30,6 @@ LL | fn f1<W: ?Sized, X: ?Sized, Y: ?Sized, Z: ?Sized>(x: &X) {
 LL |     let y: (isize, (Z, usize));
    |            ^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Z`
    = note: only the last element of a tuple may have a dynamically sized type
 
 error[E0277]: the size for values of type `X` cannot be known at compilation time
@@ -43,7 +40,6 @@ LL | fn f2<X: ?Sized, Y: ?Sized>(x: &X) {
 LL |     let y: X;
    |         ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: all local variables must have a statically known size
    = help: unsized locals are gated as an unstable feature
 
@@ -56,7 +52,6 @@ LL | fn f2<X: ?Sized, Y: ?Sized>(x: &X) {
 LL |     let y: (isize, (Y, isize));
    |            ^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Y`
    = note: only the last element of a tuple may have a dynamically sized type
 
 error[E0277]: the size for values of type `X` cannot be known at compilation time
@@ -67,7 +62,6 @@ LL | fn f3<X: ?Sized>(x1: Box<X>, x2: Box<X>, x3: Box<X>) {
 LL |     let y: X = *x1;
    |         ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: all local variables must have a statically known size
    = help: unsized locals are gated as an unstable feature
 
@@ -80,7 +74,6 @@ LL | fn f3<X: ?Sized>(x1: Box<X>, x2: Box<X>, x3: Box<X>) {
 LL |     let y = *x2;
    |         ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: all local variables must have a statically known size
    = help: unsized locals are gated as an unstable feature
 
@@ -93,7 +86,6 @@ LL | fn f3<X: ?Sized>(x1: Box<X>, x2: Box<X>, x3: Box<X>) {
 LL |     let (y, z) = (*x3, 4);
    |          ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: all local variables must have a statically known size
    = help: unsized locals are gated as an unstable feature
 
@@ -105,7 +97,6 @@ LL | fn f4<X: ?Sized + T>(x1: Box<X>, x2: Box<X>, x3: Box<X>) {
 LL |     let y: X = *x1;
    |         ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: all local variables must have a statically known size
    = help: unsized locals are gated as an unstable feature
 
@@ -118,7 +109,6 @@ LL | fn f4<X: ?Sized + T>(x1: Box<X>, x2: Box<X>, x3: Box<X>) {
 LL |     let y = *x2;
    |         ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: all local variables must have a statically known size
    = help: unsized locals are gated as an unstable feature
 
@@ -131,7 +121,6 @@ LL | fn f4<X: ?Sized + T>(x1: Box<X>, x2: Box<X>, x3: Box<X>) {
 LL |     let (y, z) = (*x3, 4);
    |          ^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = note: all local variables must have a statically known size
    = help: unsized locals are gated as an unstable feature
 
@@ -143,7 +132,6 @@ LL | fn g1<X: ?Sized>(x: X) {}
    |       |
    |       this type parameter needs to be `std::marker::Sized`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = help: unsized locals are gated as an unstable feature
 help: function arguments must have a statically known size, borrowed types always have a known size
    |
@@ -158,7 +146,6 @@ LL | fn g2<X: ?Sized + T>(x: X) {}
    |       |
    |       this type parameter needs to be `std::marker::Sized`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
    = help: unsized locals are gated as an unstable feature
 help: function arguments must have a statically known size, borrowed types always have a known size
    |
diff --git a/src/test/ui/unsized7.stderr b/src/test/ui/unsized7.stderr
index 868c9ea429e..7dbddd4ed24 100644
--- a/src/test/ui/unsized7.stderr
+++ b/src/test/ui/unsized7.stderr
@@ -9,7 +9,6 @@ LL | impl<X: ?Sized + T> T1<X> for S3<X> {
    |      |
    |      this type parameter needs to be `std::marker::Sized`
    |
-   = help: the trait `std::marker::Sized` is not implemented for `X`
 help: consider relaxing the implicit `Sized` restriction
    |
 LL | trait T1<Z: T + ?Sized> {