error[E0391]: cycle detected when simplifying constant for the type system `FOO` --> $DIR/cycle_crash.rs:3:1 | LL | const FOO: usize = FOO; | ^^^^^^^^^^^^^^^^ | note: ...which requires const-evaluating + checking `FOO`... --> $DIR/cycle_crash.rs:3:20 | LL | const FOO: usize = FOO; | ^^^ = note: ...which again requires simplifying constant for the type system `FOO`, completing the cycle = note: cycle used when running analysis passes on this crate = 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`.