Overflow evaluating well-formedness requirement with empty trait bound on associated type #148349
Description
rustc 1.91.0 as well as nightly (1.93.0-nightly (2025-10-30 d5419f1e97b90741d518)) produce an overflow error when using a where clause on an associated type when the bound in the where clause is empty. While this is a pathological example, this did occur in auto-generated code (e.g. in verus).
trait SomeBound {} trait T where Self::Assoc:, // this works: //Self::Assoc: SomeBound { type Assoc; }I expected this to compile successfully (and indeed it did on Rust 1.88).
On nightly and with 1.91 (rustc 1.91.0 (f8297e351 2025-10-28)), I get the following error:
Compiling playground v0.0.1 (/playground) error[E0275]: overflow evaluating the requirement `<Self as T>::Assoc well-formed` --> src/lib.rs:4:5 | 4 | Self::Assoc:, | ^^^^^^^^^^^ | note: required by a bound in `T` --> src/lib.rs:4:5 | 3 | trait T where | - required by a bound in this trait 4 | Self::Assoc:, | ^^^^^^^^^^^ required by this bound in `T` For more information about this error, try `rustc --explain E0275`. error: could not compile `playground` (lib) due to 1 previous error