error[E0599]: no method named `my_debug` found for opaque type `impl Debug` in the current scope
  --> $DIR/call_method_on_inherent_impl_ref.rs:20:11
   |
LL |     fn my_debug(&self);
   |        -------- the method is available for `&impl Debug` here
...
LL |         x.my_debug();
   |           ^^^^^^^^ method not found in `impl Debug`
   |
   = help: items from traits can only be used if the trait is implemented and in scope
note: `MyDebug` defines an item `my_debug`, perhaps you need to implement it
  --> $DIR/call_method_on_inherent_impl_ref.rs:4:1
   |
LL | trait MyDebug {
   | ^^^^^^^^^^^^^

error[E0391]: cycle detected when computing type of opaque `my_foo::{opaque#0}`
  --> $DIR/call_method_on_inherent_impl_ref.rs:15:16
   |
LL | fn my_foo() -> impl std::fmt::Debug {
   |                ^^^^^^^^^^^^^^^^^^^^
   |
note: ...which requires type-checking `my_foo`...
  --> $DIR/call_method_on_inherent_impl_ref.rs:20:9
   |
LL |         x.my_debug();
   |         ^
   = note: ...which requires evaluating trait selection obligation `my_foo::{opaque#0}: core::marker::Unpin`...
   = note: ...which again requires computing type of opaque `my_foo::{opaque#0}`, completing the cycle
note: cycle used when computing type of `my_foo::{opaque#0}`
  --> $DIR/call_method_on_inherent_impl_ref.rs:15:16
   |
LL | fn my_foo() -> impl 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

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0391, E0599.
For more information about an error, try `rustc --explain E0391`.