diff --git a/src/test/ui/generic-associated-types/parse/trait-path-expected-token.stderr b/src/test/ui/generic-associated-types/parse/trait-path-expected-token.stderr
index 051253cadc6..8abc4ccc9a5 100644
--- a/src/test/ui/generic-associated-types/parse/trait-path-expected-token.stderr
+++ b/src/test/ui/generic-associated-types/parse/trait-path-expected-token.stderr
@@ -2,7 +2,9 @@ error: expected one of `!`, `(`, `+`, `,`, `::`, `<`, or `>`, found `=`
   --> $DIR/trait-path-expected-token.rs:8:33
    |
 LL | fn f1<'a>(arg : Box<dyn X<Y = B = &'a ()>>) {}
-   |                                 ^ expected one of 7 possible tokens
+   |                               - ^ expected one of 7 possible tokens
+   |                               |
+   |                               maybe try to close unmatched angle bracket
 
 warning: the feature `generic_associated_types` is incomplete and may not be safe to use and/or cause compiler crashes
   --> $DIR/trait-path-expected-token.rs:1:12
diff --git a/src/test/ui/generic-associated-types/parse/trait-path-expressions.rs b/src/test/ui/generic-associated-types/parse/trait-path-expressions.rs
index de61cfa1cf7..5e50c6b35c9 100644
--- a/src/test/ui/generic-associated-types/parse/trait-path-expressions.rs
+++ b/src/test/ui/generic-associated-types/parse/trait-path-expressions.rs
@@ -17,7 +17,7 @@ mod error2 {
   }
 
   fn f2<'a>(arg : Box<dyn X< { 1 } = 32 >>) {}
-    //~^ ERROR: only types can be used in associated type constraints
+    //~^ ERROR: expected one of
 }
 
 fn main() {}
diff --git a/src/test/ui/generic-associated-types/parse/trait-path-expressions.stderr b/src/test/ui/generic-associated-types/parse/trait-path-expressions.stderr
index a9ba8adcaba..27e1a750b21 100644
--- a/src/test/ui/generic-associated-types/parse/trait-path-expressions.stderr
+++ b/src/test/ui/generic-associated-types/parse/trait-path-expressions.stderr
@@ -6,11 +6,13 @@ LL |   fn f1<'a>(arg : Box<dyn X< 1 = 32 >>) {}
    |                              |
    |                              while parsing a const generic argument starting here
 
-error: only types can be used in associated type constraints
-  --> $DIR/trait-path-expressions.rs:19:30
+error: expected one of `,`, `:`, or `>`, found `=`
+  --> $DIR/trait-path-expressions.rs:19:36
    |
 LL |   fn f2<'a>(arg : Box<dyn X< { 1 } = 32 >>) {}
-   |                              ^^^^^
+   |                                  - ^ expected one of `,`, `:`, or `>`
+   |                                  |
+   |                                  maybe try to close unmatched angle bracket
 
 warning: the feature `generic_associated_types` is incomplete and may not be safe to use and/or cause compiler crashes
   --> $DIR/trait-path-expressions.rs:1:12
diff --git a/src/test/ui/generic-associated-types/parse/trait-path-missing-gen_arg.stderr b/src/test/ui/generic-associated-types/parse/trait-path-missing-gen_arg.stderr
index 8a5e2c29c36..1b9de455713 100644
--- a/src/test/ui/generic-associated-types/parse/trait-path-missing-gen_arg.stderr
+++ b/src/test/ui/generic-associated-types/parse/trait-path-missing-gen_arg.stderr
@@ -28,7 +28,9 @@ error: expected one of `>`, a const expression, lifetime, or type, found `=`
   --> $DIR/trait-path-missing-gen_arg.rs:17:30
    |
 LL |   fn f1<'a>(arg : Box<dyn X< = 32 >>) {}
-   |                              ^ expected one of `>`, a const expression, lifetime, or type
+   |                            - ^ expected one of `>`, const, lifetime, or type
+   |                            |
+   |                            maybe try to close unmatched angle bracket
 
 warning: the feature `generic_associated_types` is incomplete and may not be safe to use and/or cause compiler crashes
   --> $DIR/trait-path-missing-gen_arg.rs:1:12
diff --git a/src/test/ui/generic-associated-types/parse/trait-path-segments.rs b/src/test/ui/generic-associated-types/parse/trait-path-segments.rs
index 0bf48b1f418..eba30e1438f 100644
--- a/src/test/ui/generic-associated-types/parse/trait-path-segments.rs
+++ b/src/test/ui/generic-associated-types/parse/trait-path-segments.rs
@@ -7,7 +7,7 @@ const _: () = {
     }
 
     fn f1<'a>(arg : Box<dyn X<X::Y = u32>>) {}
-        //~^ ERROR: paths with multiple segments cannot be used in associated type constraints
+        //~^ ERROR: expected one of
   };
 
 const _: () = {
@@ -18,7 +18,7 @@ const _: () = {
     trait Z {}
 
     impl<T : X<<Self as X>::Y<'a> = &'a u32>> Z for T {}
-        //~^ ERROR: qualified paths cannot be used in associated type constraints
+        //~^ ERROR: expected one of
 };
 
 const _: () = {
@@ -29,7 +29,7 @@ const _: () = {
     trait Z {}
 
     impl<T : X<X::Y<'a> = &'a u32>> Z for T {}
-        //~^ ERROR: paths with multiple segments cannot be used in associated type constraints
+        //~^ ERROR: expected one of
 };
 
 fn main() {}
diff --git a/src/test/ui/generic-associated-types/parse/trait-path-segments.stderr b/src/test/ui/generic-associated-types/parse/trait-path-segments.stderr
index 4e2b84d0182..c82953aaed7 100644
--- a/src/test/ui/generic-associated-types/parse/trait-path-segments.stderr
+++ b/src/test/ui/generic-associated-types/parse/trait-path-segments.stderr
@@ -1,22 +1,26 @@
-error: paths with multiple segments cannot be used in associated type constraints
-  --> $DIR/trait-path-segments.rs:9:31
+error: expected one of `!`, `(`, `+`, `,`, `::`, `:`, `<`, or `>`, found `=`
+  --> $DIR/trait-path-segments.rs:9:36
    |
 LL |     fn f1<'a>(arg : Box<dyn X<X::Y = u32>>) {}
-   |                               ^^^^
+   |                                  - ^ expected one of 8 possible tokens
+   |                                  |
+   |                                  maybe try to close unmatched angle bracket
 
-error: qualified paths cannot be used in associated type constraints
-  --> $DIR/trait-path-segments.rs:20:16
+error: expected one of `,`, `::`, `:`, or `>`, found `=`
+  --> $DIR/trait-path-segments.rs:20:35
    |
 LL |     impl<T : X<<Self as X>::Y<'a> = &'a u32>> Z for T {}
-   |                ^^^^^^^^^-^^^^^^^^
-   |                         |
-   |                         not allowed in associated type constraints
+   |                                 - ^ expected one of `,`, `::`, `:`, or `>`
+   |                                 |
+   |                                 maybe try to close unmatched angle bracket
 
-error: paths with multiple segments cannot be used in associated type constraints
-  --> $DIR/trait-path-segments.rs:31:16
+error: expected one of `!`, `+`, `,`, `::`, `:`, or `>`, found `=`
+  --> $DIR/trait-path-segments.rs:31:25
    |
 LL |     impl<T : X<X::Y<'a> = &'a u32>> Z for T {}
-   |                ^^^^^^^^
+   |                       - ^ expected one of `!`, `+`, `,`, `::`, `:`, or `>`
+   |                       |
+   |                       maybe try to close unmatched angle bracket
 
 warning: the feature `generic_associated_types` is incomplete and may not be safe to use and/or cause compiler crashes
   --> $DIR/trait-path-segments.rs:1:12
diff --git a/src/test/ui/generic-associated-types/parse/trait-path-types.rs b/src/test/ui/generic-associated-types/parse/trait-path-types.rs
index 6cdb501ec65..522b3edc638 100644
--- a/src/test/ui/generic-associated-types/parse/trait-path-types.rs
+++ b/src/test/ui/generic-associated-types/parse/trait-path-types.rs
@@ -7,17 +7,17 @@ trait X {
 
 const _: () = {
   fn f<'a>(arg : Box<dyn X< [u8; 1] = u32>>) {}
-      //~^ ERROR: only path types can be used in associated type constraints
+      //~^ ERROR: expected one of
 };
 
 const _: () = {
   fn f1<'a>(arg : Box<dyn X<(Y<'a>) = &'a ()>>) {}
-      //~^ ERROR: only path types can be used in associated type constraints
+      //~^ ERROR: expected one of
 };
 
 const _: () = {
   fn f1<'a>(arg : Box<dyn X< 'a = u32 >>) {}
-      //~^ ERROR: only types can be used in associated type constraints
+      //~^ ERROR: expected one of
 };
 
 fn main() {}
diff --git a/src/test/ui/generic-associated-types/parse/trait-path-types.stderr b/src/test/ui/generic-associated-types/parse/trait-path-types.stderr
index f5be084613b..ac791c22481 100644
--- a/src/test/ui/generic-associated-types/parse/trait-path-types.stderr
+++ b/src/test/ui/generic-associated-types/parse/trait-path-types.stderr
@@ -1,20 +1,26 @@
-error: only path types can be used in associated type constraints
-  --> $DIR/trait-path-types.rs:9:29
+error: expected one of `,`, `:`, or `>`, found `=`
+  --> $DIR/trait-path-types.rs:9:37
    |
 LL |   fn f<'a>(arg : Box<dyn X< [u8; 1] = u32>>) {}
-   |                             ^^^^^^^
+   |                                   - ^ expected one of `,`, `:`, or `>`
+   |                                   |
+   |                                   maybe try to close unmatched angle bracket
 
-error: only path types can be used in associated type constraints
-  --> $DIR/trait-path-types.rs:14:29
+error: expected one of `,`, `:`, or `>`, found `=`
+  --> $DIR/trait-path-types.rs:14:37
    |
 LL |   fn f1<'a>(arg : Box<dyn X<(Y<'a>) = &'a ()>>) {}
-   |                             ^^^^^^^
+   |                                   - ^ expected one of `,`, `:`, or `>`
+   |                                   |
+   |                                   maybe try to close unmatched angle bracket
 
-error: only types can be used in associated type constraints
-  --> $DIR/trait-path-types.rs:19:30
+error: expected one of `,`, `:`, or `>`, found `=`
+  --> $DIR/trait-path-types.rs:19:33
    |
 LL |   fn f1<'a>(arg : Box<dyn X< 'a = u32 >>) {}
-   |                              ^^
+   |                              -- ^ expected one of `,`, `:`, or `>`
+   |                              |
+   |                              maybe try to close unmatched angle bracket
 
 warning: the feature `generic_associated_types` is incomplete and may not be safe to use and/or cause compiler crashes
   --> $DIR/trait-path-types.rs:1:12
diff --git a/src/test/ui/issues/issue-34334.rs b/src/test/ui/issues/issue-34334.rs
index b45c00f6943..51486bc40de 100644
--- a/src/test/ui/issues/issue-34334.rs
+++ b/src/test/ui/issues/issue-34334.rs
@@ -1,6 +1,8 @@
 fn main () {
     let sr: Vec<(u32, _, _) = vec![];
-    //~^ ERROR only path types can be used in associated type constraints
+    //~^ ERROR expected one of
+
     let sr2: Vec<(u32, _, _)> = sr.iter().map(|(faction, th_sender, th_receiver)| {}).collect();
     //~^ ERROR a value of type `Vec<(u32, _, _)>` cannot be built
+
 }
diff --git a/src/test/ui/issues/issue-34334.stderr b/src/test/ui/issues/issue-34334.stderr
index a9b9bf06d7f..acb44ce2c35 100644
--- a/src/test/ui/issues/issue-34334.stderr
+++ b/src/test/ui/issues/issue-34334.stderr
@@ -1,13 +1,14 @@
-error: only path types can be used in associated type constraints
-  --> $DIR/issue-34334.rs:2:17
+error: expected one of `,`, `:`, or `>`, found `=`
+  --> $DIR/issue-34334.rs:2:29
    |
 LL |     let sr: Vec<(u32, _, _) = vec![];
-   |         --      ^^^^^^^^^^^
-   |         |
+   |         --                - ^ expected one of `,`, `:`, or `>`
+   |         |                 |
+   |         |                 maybe try to close unmatched angle bracket
    |         while parsing the type for `sr`
 
 error[E0277]: a value of type `Vec<(u32, _, _)>` cannot be built from an iterator over elements of type `()`
-  --> $DIR/issue-34334.rs:4:87
+  --> $DIR/issue-34334.rs:5:87
    |
 LL |     let sr2: Vec<(u32, _, _)> = sr.iter().map(|(faction, th_sender, th_receiver)| {}).collect();
    |                                                                                       ^^^^^^^ value of type `Vec<(u32, _, _)>` cannot be built from `std::iter::Iterator<Item=()>`
diff --git a/src/test/ui/parser/missing-closing-angle-bracket-eq-constraint.rs b/src/test/ui/parser/missing-closing-angle-bracket-eq-constraint.rs
new file mode 100644
index 00000000000..da95c1bfa27
--- /dev/null
+++ b/src/test/ui/parser/missing-closing-angle-bracket-eq-constraint.rs
@@ -0,0 +1,23 @@
+struct Foo<T1, T2> {
+  _a : T1,
+  _b : T2,
+}
+
+fn test1<T>(arg : T) {
+  let v : Vec<(u32,_) = vec![];
+    //~^ ERROR: expected one of
+    //~| ERROR: type annotations needed
+}
+
+fn test2<T1, T2>(arg1 : T1, arg2 : T2) {
+  let foo : Foo::<T1, T2 = Foo {_a : arg1, _b : arg2};
+    //~^ ERROR: expected one of
+}
+
+fn test3<'a>(arg : &'a u32) {
+  let v : Vec<'a = vec![];
+    //~^ ERROR: expected one of
+    //~| ERROR: type annotations needed for `Vec<T>`
+}
+
+fn main() {}
diff --git a/src/test/ui/parser/missing-closing-angle-bracket-eq-constraint.stderr b/src/test/ui/parser/missing-closing-angle-bracket-eq-constraint.stderr
new file mode 100644
index 00000000000..ae53334f5e0
--- /dev/null
+++ b/src/test/ui/parser/missing-closing-angle-bracket-eq-constraint.stderr
@@ -0,0 +1,49 @@
+error: expected one of `,`, `:`, or `>`, found `=`
+  --> $DIR/missing-closing-angle-bracket-eq-constraint.rs:7:23
+   |
+LL |   let v : Vec<(u32,_) = vec![];
+   |       -             - ^ expected one of `,`, `:`, or `>`
+   |       |             |
+   |       |             maybe try to close unmatched angle bracket
+   |       while parsing the type for `v`
+
+error: expected one of `!`, `(`, `+`, `,`, `::`, `<`, or `>`, found `{`
+  --> $DIR/missing-closing-angle-bracket-eq-constraint.rs:13:32
+   |
+LL |   let foo : Foo::<T1, T2 = Foo {_a : arg1, _b : arg2};
+   |       ---                      ^ expected one of 7 possible tokens
+   |       |
+   |       while parsing the type for `foo`
+
+error: expected one of `,`, `:`, or `>`, found `=`
+  --> $DIR/missing-closing-angle-bracket-eq-constraint.rs:18:18
+   |
+LL |   let v : Vec<'a = vec![];
+   |       -       -- ^ expected one of `,`, `:`, or `>`
+   |       |       |
+   |       |       maybe try to close unmatched angle bracket
+   |       while parsing the type for `v`
+
+error[E0282]: type annotations needed for `Vec<T>`
+  --> $DIR/missing-closing-angle-bracket-eq-constraint.rs:7:25
+   |
+LL |   let v : Vec<(u32,_) = vec![];
+   |       -                 ^^^^^^ cannot infer type for type parameter `T`
+   |       |
+   |       consider giving `v` the explicit type `Vec<T>`, where the type parameter `T` is specified
+   |
+   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0282]: type annotations needed for `Vec<T>`
+  --> $DIR/missing-closing-angle-bracket-eq-constraint.rs:18:20
+   |
+LL |   let v : Vec<'a = vec![];
+   |       -            ^^^^^^ cannot infer type for type parameter `T`
+   |       |
+   |       consider giving `v` the explicit type `Vec<T>`, where the type parameter `T` is specified
+   |
+   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 5 previous errors
+
+For more information about this error, try `rustc --explain E0282`.
diff --git a/src/test/ui/parser/nested-missing-closing-angle-bracket.rs b/src/test/ui/parser/nested-missing-closing-angle-bracket.rs
new file mode 100644
index 00000000000..84ffdd176ae
--- /dev/null
+++ b/src/test/ui/parser/nested-missing-closing-angle-bracket.rs
@@ -0,0 +1,4 @@
+fn main() {
+  let v : Vec::<Vec<(u32,_,_)> = vec![vec![]];
+    //~^ ERROR: expected one of
+}
diff --git a/src/test/ui/parser/nested-missing-closing-angle-bracket.stderr b/src/test/ui/parser/nested-missing-closing-angle-bracket.stderr
new file mode 100644
index 00000000000..b85bc02568c
--- /dev/null
+++ b/src/test/ui/parser/nested-missing-closing-angle-bracket.stderr
@@ -0,0 +1,8 @@
+error: expected one of `,` or `>`, found `;`
+  --> $DIR/nested-missing-closing-angle-bracket.rs:2:46
+   |
+LL |   let v : Vec::<Vec<(u32,_,_)> = vec![vec![]];
+   |       - while parsing the type for `v`       ^ expected one of `,` or `>`
+
+error: aborting due to previous error
+