error[E0282]: type annotations needed
  --> $DIR/issue-65611.rs:59:20
   |
LL |     let x = buffer.last().unwrap().0.clone();
   |             -------^^^^--
   |             |      |
   |             |      cannot infer type for type parameter `T`
   |             this method call resolves to `Option<&T>`
   |
   = note: type must be known at this point

error[E0609]: no field `0` on type `&_`
  --> $DIR/issue-65611.rs:59:36
   |
LL |     let x = buffer.last().unwrap().0.clone();
   |                                    ^

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0282, E0609.
For more information about an error, try `rustc --explain E0282`.