error[E0308]: mismatched types
  --> $DIR/non-whitespace-trimming.rs:4:241
   |
LL | ... = (); let _: () = (); let _: () = (); let _: () = 42; let _: () = (); let _: () = (); let _: () = (); let _: () = (); let _: () = ();...
   |                                                       ^^ expected (), found integer
   |
