warning: unreachable predicate
  --> $DIR/cfg_select.rs:52:5
   |
LL |     _ => {}
   |     - always matches
LL |     true => {}
   |     ^^^^ this predicate is never reached

error: none of the predicates in this `cfg_select` evaluated to true
  --> $DIR/cfg_select.rs:56:1
   |
LL | / cfg_select! {
LL | |
LL | |     false => {}
LL | | }
   | |_^

error: none of the predicates in this `cfg_select` evaluated to true
  --> $DIR/cfg_select.rs:61:1
   |
LL | cfg_select! {}
   | ^^^^^^^^^^^^^^

error: aborting due to 2 previous errors; 1 warning emitted