error[E0391]: cycle detected when const-evaluating + checking `FOO` --> $DIR/issue-17252.rs:1:20 | LL | const FOO: usize = FOO; | ^^^ | = note: ...which immediately requires const-evaluating + checking `FOO` again note: cycle used when const-evaluating + checking `main::{constant#0}` --> $DIR/issue-17252.rs:4:18 | LL | let _x: [u8; FOO]; // caused stack overflow prior to fix | ^^^ error: aborting due to previous error For more information about this error, try `rustc --explain E0391`.