Auto merge of #126037 - matthiaskrgr:rollup-7pz1nhr, r=matthiaskrgr

Rollup of 10 pull requests

Successful merges:

 - #124746 (`rustc --explain E0582` additional example)
 - #125407 (Detect when user is trying to create a lending `Iterator` and give a custom explanation)
 - #125505 (Add intra-doc-links to rustc_middle crate-level docs.)
 - #125792 (Don't drop `Unsize` candidate in intercrate mode)
 - #125819 (Various `HirTyLowerer` cleanups)
 - #125861 (rustc_codegen_ssa: fix `get_rpath_relative_to_output` panic when lib only contains file name)
 - #125911 (delete bootstrap build before switching to bumped rustc)
 - #125921 (coverage: Carve out hole spans in a separate early pass)
 - #125940 (std::unix::fs::get_path: using fcntl codepath for netbsd instead.)
 - #126022 (set `has_unconstrained_ty_var` when generalizing aliases in bivariant contexts)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 34 insertions, 0 deletions

diff --git a/compiler/rustc_error_codes/src/error_codes/E0582.md b/compiler/rustc_error_codes/src/error_codes/E0582.md
index e50cc60ea33..b2cdb509c95 100644
--- a/compiler/rustc_error_codes/src/error_codes/E0582.md
+++ b/compiler/rustc_error_codes/src/error_codes/E0582.md
@@ -27,6 +27,40 @@ fn bar<F, G>(t: F, u: G)
 fn main() { }
 ```
 
+This error also includes the use of associated types with lifetime parameters.
+```compile_fail,E0582
+trait Foo {
+    type Assoc<'a>;
+}
+
+struct Bar<X, F>
+where
+    X: Foo,
+    F: for<'a> Fn(X::Assoc<'a>) -> &'a i32
+{
+    x: X,
+    f: F
+}
+```
+The latter scenario encounters this error because `Foo::Assoc<'a>` could be
+implemented by a type that does not use the `'a` parameter, so there is no
+guarentee that `X::Assoc<'a>` actually uses `'a`.
+
+To fix this we can pass a dummy parameter:
+```
+# trait Foo {
+#     type Assoc<'a>;
+# }
+struct Bar<X, F>
+where
+    X: Foo,
+    F: for<'a> Fn(X::Assoc<'a>, /* dummy */ &'a ()) -> &'a i32
+{
+    x: X,
+    f: F
+}
+```
+
 Note: The examples above used to be (erroneously) accepted by the
 compiler, but this was since corrected. See [issue #33685] for more
 details.