safe_packed_borrows warning on wingdi::BITMAPFILEHEADER

[Arnavion]

warning: #[derive] can't be used on a #[repr(packed)] struct that does not derive Copy (error E0133)
   --> src\macros.rs:354:54
    |
354 |           STRUCT!{#[cfg_attr(feature = "debug", derive(Debug))] $($rest)*}
    |                                                        ^^^^^
    |
   ::: src\um\wingdi.rs:599:1
    |
599 | / STRUCT!{ #[debug] #[repr(packed)] struct BITMAPFILEHEADER {
600 | |     bfType: WORD,
601 | |     bfSize: DWORD,
602 | |     bfReserved1: WORD,
603 | |     bfReserved2: WORD,
604 | |     bfOffBits: DWORD,
605 | | }}
    | |__- in this macro invocation
    |
    = note: #[warn(safe_packed_borrows)] on by default
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #46043 <https://github.com/rust-lang/rust/issues/46043>

[retep998]

This is a known issue in Rust rust-lang/rust#50826

[Arnavion]

Yeah, it happens if there's an explicit impl. If you #[derive(Copy)] it goes away.