error[E0391]: cycle detected when simplifying constant for the type system `FOO`
  --> $DIR/issue-17252.rs:1:1
   |
LL | const FOO: usize = FOO;
   | ^^^^^^^^^^^^^^^^
   |
note: ...which requires const-evaluating + checking `FOO`...
  --> $DIR/issue-17252.rs:1:20
   |
LL | const FOO: usize = FOO;
   |                    ^^^
   = note: ...which again requires simplifying constant for the type system `FOO`, completing the cycle
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
   |                  ^^^
   = 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`.