error[E0391]: cycle detected when const-evaluating + checking `X::A::{constant#0}` --> $DIR/issue-23302-1.rs:4:9 | LL | A = X::A as isize, | ^^^^^^^^^^^^^ | = note: ...which immediately requires const-evaluating + checking `X::A::{constant#0}` again note: cycle used when simplifying constant for the type system `X::A::{constant#0}` --> $DIR/issue-23302-1.rs:4:9 | LL | A = X::A as isize, | ^^^^^^^^^^^^^ = 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 previous error For more information about this error, try `rustc --explain E0391`.