error[E0391]: cycle detected when computing type of `<impl at $DIR/method-compatability-via-leakage-cycle.rs:17:1: 17:19>::foo::{anon_assoc#0}`
  --> $DIR/method-compatability-via-leakage-cycle.rs:21:24
   |
LL |     fn foo(b: bool) -> impl Sized {
   |                        ^^^^^^^^^^
   |
note: ...which requires comparing an impl and trait method signature, inferring any hidden `impl Trait` types in the process...
  --> $DIR/method-compatability-via-leakage-cycle.rs:21:24
   |
LL |     fn foo(b: bool) -> impl Sized {
   |                        ^^^^^^^^^^
   = note: ...which requires evaluating trait selection obligation `<impl at $DIR/method-compatability-via-leakage-cycle.rs:17:1: 17:19>::foo::{opaque#0}: core::marker::Send`...
note: ...which requires computing type of opaque `<impl at $DIR/method-compatability-via-leakage-cycle.rs:17:1: 17:19>::foo::{opaque#0}`...
  --> $DIR/method-compatability-via-leakage-cycle.rs:21:24
   |
LL |     fn foo(b: bool) -> impl Sized {
   |                        ^^^^^^^^^^
note: ...which requires borrow-checking `<impl at $DIR/method-compatability-via-leakage-cycle.rs:17:1: 17:19>::foo`...
  --> $DIR/method-compatability-via-leakage-cycle.rs:21:5
   |
LL |     fn foo(b: bool) -> impl Sized {
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: ...which requires promoting constants in MIR for `<impl at $DIR/method-compatability-via-leakage-cycle.rs:17:1: 17:19>::foo`...
  --> $DIR/method-compatability-via-leakage-cycle.rs:21:5
   |
LL |     fn foo(b: bool) -> impl Sized {
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: ...which requires checking if `<impl at $DIR/method-compatability-via-leakage-cycle.rs:17:1: 17:19>::foo` contains FFI-unwind calls...
  --> $DIR/method-compatability-via-leakage-cycle.rs:21:5
   |
LL |     fn foo(b: bool) -> impl Sized {
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: ...which requires building MIR for `<impl at $DIR/method-compatability-via-leakage-cycle.rs:17:1: 17:19>::foo`...
  --> $DIR/method-compatability-via-leakage-cycle.rs:21:5
   |
LL |     fn foo(b: bool) -> impl Sized {
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: ...which requires match-checking `<impl at $DIR/method-compatability-via-leakage-cycle.rs:17:1: 17:19>::foo`...
  --> $DIR/method-compatability-via-leakage-cycle.rs:21:5
   |
LL |     fn foo(b: bool) -> impl Sized {
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: ...which requires type-checking `<impl at $DIR/method-compatability-via-leakage-cycle.rs:17:1: 17:19>::foo`...
  --> $DIR/method-compatability-via-leakage-cycle.rs:21:5
   |
LL |     fn foo(b: bool) -> impl Sized {
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   = note: ...which again requires computing type of `<impl at $DIR/method-compatability-via-leakage-cycle.rs:17:1: 17:19>::foo::{anon_assoc#0}`, completing the cycle
note: cycle used when checking assoc item `<impl at $DIR/method-compatability-via-leakage-cycle.rs:17:1: 17:19>::foo` is compatible with trait definition
  --> $DIR/method-compatability-via-leakage-cycle.rs:21:5
   |
LL |     fn foo(b: bool) -> impl Sized {
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   = 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 1 previous error

For more information about this error, try `rustc --explain E0391`.