error[E0308]: mismatched types
  --> $DIR/closure-print-generic-trim-off-verbose-2.rs:9:23
   |
LL |         let c = || println!("{} {}", t, x);
   |                 -- the found closure
LL |         let c1 : () = c;
   |                  --   ^ expected `()`, found closure
   |                  |
   |                  expected due to this
   |
   = note: expected unit type `()`
                found closure `{mod1::f<T>::{closure#0} closure_args=(unavailable) args=[T, ?16t, extern "rust-call" fn(()), ?15t]}`
help: use parentheses to call this closure
   |
LL |         let c1 : () = c();
   |                        ++

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0308`.