selection error diagnostics results in a query cycle #145611
Description
when fetching effective_visibilities for Adt self types of a local trait while proving a where-clause.
rust/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
Lines 2871 to 2889 in 8c32e31
This query fetches the hidden type of all opaque types
rust/compiler/rustc_privacy/src/lib.rs
Lines 1841 to 1846 in 8c32e31
introduced in #143431, cc @xizheyin @compiler-errors
trait LocalTrait {}
struct SomeType;
fn impls_trait<T: LocalTrait>() {}
fn foo() -> impl Sized {
impls_trait::<SomeType>();
}results in
error[E0391]: cycle detected when computing type of `foo::{opaque#0}`
--> src/lib.rs:4:13
|
4 | fn foo() -> impl Sized {
| ^^^^^^^^^^
|
note: ...which requires computing type of opaque `foo::{opaque#0}`...
--> src/lib.rs:4:13
|
4 | fn foo() -> impl Sized {
| ^^^^^^^^^^
note: ...which requires borrow-checking `foo`...
--> src/lib.rs:4:1
|
4 | fn foo() -> impl Sized {
| ^^^^^^^^^^^^^^^^^^^^^^
note: ...which requires promoting constants in MIR for `foo`...
--> src/lib.rs:4:1
|
4 | fn foo() -> impl Sized {
| ^^^^^^^^^^^^^^^^^^^^^^
note: ...which requires checking if `foo` contains FFI-unwind calls...
--> src/lib.rs:4:1
|
4 | fn foo() -> impl Sized {
| ^^^^^^^^^^^^^^^^^^^^^^
note: ...which requires building MIR for `foo`...
--> src/lib.rs:4:1
|
4 | fn foo() -> impl Sized {
| ^^^^^^^^^^^^^^^^^^^^^^
note: ...which requires match-checking `foo`...
--> src/lib.rs:4:1
|
4 | fn foo() -> impl Sized {
| ^^^^^^^^^^^^^^^^^^^^^^
note: ...which requires type-checking `foo`...
--> src/lib.rs:4:1
|
4 | fn foo() -> impl Sized {
| ^^^^^^^^^^^^^^^^^^^^^^
= note: ...which requires checking effective visibilities...
= note: ...which again requires computing type of `foo::{opaque#0}`, completing the cycle
note: cycle used when checking that `foo::{opaque#0}` is well-formed
--> src/lib.rs:4:13
|
4 | fn foo() -> 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[E0277]: the trait bound `SomeType: LocalTrait` is not satisfied
--> src/lib.rs:5:19
|
5 | impls_trait::<SomeType>();
| ^^^^^^^^ the trait `LocalTrait` is not implemented for `SomeType`
|
help: this trait has no implementations, consider adding one
--> src/lib.rs:1:1
|
1 | trait LocalTrait {}
| ^^^^^^^^^^^^^^^^
note: required by a bound in `impls_trait`
--> src/lib.rs:3:19
|
3 | fn impls_trait<T: LocalTrait>() {}
| ^^^^^^^^^^ required by this bound in `impls_trait`
note the query cycle before the actually desired error