Add issue reference

diff --git a/src/libcore/future/mod.rs b/src/libcore/future/mod.rs
index 6ee8479b34780000c032eebc5839ca0aa367376c..8dfda7a4a32366447668ff4b6ed79662457be66e 100644 (file)
--- a/src/libcore/future/mod.rs
+++ b/src/libcore/future/mod.rs
@@ -17,7 +17,7 @@
 /// This type is needed because:
 ///
 /// a) Generators cannot implement `for<'a, 'b> Generator<&'a mut Context<'b>>`, so we need to pass
-///    a raw pointer.
+///    a raw pointer (see https://github.com/rust-lang/rust/issues/68923).
 /// b) Raw pointers and `NonNull` aren't `Send` or `Sync`, so that would make every single future
 ///    non-Send/Sync as well, and we don't want that.
 ///