error: `derive` cannot be used on items with type macros --> $DIR/nonsense-input-to-debug.rs:7:22 | LL | should_be_vec_t: vec![T], | ^^^^^^^ error: expected type, found `expr` metavariable --> $DIR/nonsense-input-to-debug.rs:7:22 | LL | should_be_vec_t: vec![T], | ^^^^^^^ | | | expected type | in this macro invocation | this macro call doesn't expand to a type | = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info) error[E0392]: type parameter `T` is never used --> $DIR/nonsense-input-to-debug.rs:5:17 | LL | struct Nonsense { | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead error: aborting due to 3 previous errors For more information about this error, try `rustc --explain E0392`.