error[E02001]: duplicate declaration, item, or annotation
  ┌─ tests/move_check/expansion/duplicate_alias.move:8:19
  │
7 │     use 0x2::X as Z;
  │                   - Alias previously defined here
8 │     use 0x2::Y as Z;
  │                   ^ Duplicate module alias 'Z'. Module aliases must be unique within a given namespace

warning[W09001]: unused alias
  ┌─ tests/move_check/expansion/duplicate_alias.move:8:19
  │
8 │     use 0x2::Y as Z;
  │                   ^ Unused 'use' of alias 'Z'. Consider removing it