error: variant `Dead` is never constructed
  --> $DIR/issue-41883.rs:4:5
   |
LL | enum Category {
   |      -------- variant in this enum
LL |     Dead,
   |     ^^^^
   |
note: the lint level is defined here
  --> $DIR/issue-41883.rs:1:9
   |
LL | #![deny(dead_code)]
   |         ^^^^^^^^^

error: trait `UnusedTrait` is never used
  --> $DIR/issue-41883.rs:8:7
   |
LL | trait UnusedTrait {
   |       ^^^^^^^^^^^

error: struct `UnusedStruct` is never constructed
  --> $DIR/issue-41883.rs:14:8
   |
LL | struct UnusedStruct;
   |        ^^^^^^^^^^^^

error: struct `UnusedStruct` is never constructed
  --> $DIR/issue-41883.rs:24:12
   |
LL |     struct UnusedStruct;
   |            ^^^^^^^^^^^^

error: aborting due to 4 previous errors