added links as a note

Author: RickleAndMortimer

compiler/rustc_query_system/messages.ftl

@@ -1,4 +1,5 @@
-query_system_cycle = cycle detected when {$stack_bottom}. see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information.
+query_system_cycle = cycle detected when {$stack_bottom}
+    .note = see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 query_system_cycle_recursive_trait_alias = trait aliases cannot be recursive
 

compiler/rustc_query_system/src/error.rs

@@ -46,6 +46,7 @@ pub struct CycleUsage {
 #[derive(Diagnostic)]
 #[diag(query_system_cycle, code = "E0391")]
 pub struct Cycle {
+    #[note]
     #[primary_span]
     pub span: Span,
     pub stack_bottom: String,

tests/rustdoc-ui/issue-110629-private-type-cycle-dyn.stderr

@@ -1,9 +1,14 @@
-error[E0391]: cycle detected when expanding type alias `Bar`. see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information.
+error[E0391]: cycle detected when expanding type alias `Bar`
   --> $DIR/issue-110629-private-type-cycle-dyn.rs:1:38
    |
 LL | type Bar<'a, 'b> = Box<dyn PartialEq<Bar<'a, 'b>>>;
    |                                      ^^^^^^^^^^^
    |
+note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
+  --> $DIR/issue-110629-private-type-cycle-dyn.rs:1:38
+   |
+LL | type Bar<'a, 'b> = Box<dyn PartialEq<Bar<'a, 'b>>>;
+   |                                      ^^^^^^^^^^^
    = note: ...which immediately requires expanding type alias `Bar` again
    = note: type aliases cannot be recursive
    = help: consider using a struct, enum, or union instead to break the cycle

tests/ui/associated-consts/defaults-cyclic-fail.stderr

@@ -1,9 +1,14 @@
-error[E0391]: cycle detected when const-evaluating + checking `Tr::A`. see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information.
+error[E0391]: cycle detected when const-evaluating + checking `Tr::A`
   --> $DIR/defaults-cyclic-fail.rs:5:19
    |
 LL |     const A: u8 = Self::B;
    |                   ^^^^^^^
    |
+note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
+  --> $DIR/defaults-cyclic-fail.rs:5:19
+   |
+LL |     const A: u8 = Self::B;
+   |                   ^^^^^^^
 note: ...which requires const-evaluating + checking `Tr::B`...
   --> $DIR/defaults-cyclic-fail.rs:8:19
    |

tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-impl.stderr

@@ -1,9 +1,14 @@
-error[E0391]: cycle detected when elaborating drops for `<impl at $DIR/issue-24949-assoc-const-static-recursion-impl.rs:11:1: 11:19>::BAR`. see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information.
+error[E0391]: cycle detected when elaborating drops for `<impl at $DIR/issue-24949-assoc-const-static-recursion-impl.rs:11:1: 11:19>::BAR`
   --> $DIR/issue-24949-assoc-const-static-recursion-impl.rs:12:22
    |
 LL |     const BAR: u32 = IMPL_REF_BAR;
    |                      ^^^^^^^^^^^^
    |
+note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
+  --> $DIR/issue-24949-assoc-const-static-recursion-impl.rs:12:22
+   |
+LL |     const BAR: u32 = IMPL_REF_BAR;
+   |                      ^^^^^^^^^^^^
 note: ...which requires const-evaluating + checking `IMPL_REF_BAR`...
   --> $DIR/issue-24949-assoc-const-static-recursion-impl.rs:7:1
    |

tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait-default.stderr

@@ -1,9 +1,14 @@
-error[E0391]: cycle detected when elaborating drops for `FooDefault::BAR`. see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information.
+error[E0391]: cycle detected when elaborating drops for `FooDefault::BAR`
   --> $DIR/issue-24949-assoc-const-static-recursion-trait-default.rs:8:22
    |
 LL |     const BAR: u32 = DEFAULT_REF_BAR;
    |                      ^^^^^^^^^^^^^^^
    |
+note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
+  --> $DIR/issue-24949-assoc-const-static-recursion-trait-default.rs:8:22
+   |
+LL |     const BAR: u32 = DEFAULT_REF_BAR;
+   |                      ^^^^^^^^^^^^^^^
 note: ...which requires const-evaluating + checking `DEFAULT_REF_BAR`...
   --> $DIR/issue-24949-assoc-const-static-recursion-trait-default.rs:11:1
    |

tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait.stderr

@@ -1,9 +1,14 @@
-error[E0391]: cycle detected when elaborating drops for `<impl at $DIR/issue-24949-assoc-const-static-recursion-trait.rs:11:1: 11:28>::BAR`. see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information.
+error[E0391]: cycle detected when elaborating drops for `<impl at $DIR/issue-24949-assoc-const-static-recursion-trait.rs:11:1: 11:28>::BAR`
   --> $DIR/issue-24949-assoc-const-static-recursion-trait.rs:12:22
    |
 LL |     const BAR: u32 = TRAIT_REF_BAR;
    |                      ^^^^^^^^^^^^^
    |
+note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
+  --> $DIR/issue-24949-assoc-const-static-recursion-trait.rs:12:22
+   |
+LL |     const BAR: u32 = TRAIT_REF_BAR;
+   |                      ^^^^^^^^^^^^^
 note: ...which requires const-evaluating + checking `TRAIT_REF_BAR`...
   --> $DIR/issue-24949-assoc-const-static-recursion-trait.rs:7:1
    |

tests/ui/associated-inherent-types/bugs/cycle-iat-inside-of-adt.stderr

@@ -1,9 +1,14 @@
-error[E0391]: cycle detected when computing predicates of `Foo`. see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information.
+error[E0391]: cycle detected when computing predicates of `Foo`
   --> $DIR/cycle-iat-inside-of-adt.rs:7:1
    |
 LL | struct Foo {
    | ^^^^^^^^^^
    |
+note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
+  --> $DIR/cycle-iat-inside-of-adt.rs:7:1
+   |
+LL | struct Foo {
+   | ^^^^^^^^^^
 note: ...which requires computing predicates of `Foo`...
   --> $DIR/cycle-iat-inside-of-adt.rs:7:1
    |

tests/ui/associated-inherent-types/bugs/cycle-iat-inside-of-where-predicate.stderr

@@ -1,9 +1,14 @@
-error[E0391]: cycle detected when computing predicates of `user`. see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information.
+error[E0391]: cycle detected when computing predicates of `user`
   --> $DIR/cycle-iat-inside-of-where-predicate.rs:8:1
    |
 LL | fn user<T>() where S<T>::P: std::fmt::Debug {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
+  --> $DIR/cycle-iat-inside-of-where-predicate.rs:8:1
+   |
+LL | fn user<T>() where S<T>::P: std::fmt::Debug {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 note: ...which requires computing predicates of `user`...
   --> $DIR/cycle-iat-inside-of-where-predicate.rs:8:1
    |

tests/ui/associated-type-bounds/ambiguous-associated-type2.rs

@@ -5,7 +5,7 @@ trait Bar<T> {
     type Item;
 }
 trait Baz: Foo + Bar<Self::Item> {}
-//~^ ERROR cycle detected when computing the super traits of `Baz` with associated type name `Item`. see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information. [E0391]
+//~^ ERROR cycle detected when computing the super traits of `Baz` with associated type name `Item` [E0391]
 
 
 fn main() {}