warning: byte slice in a packed struct that derives a built-in trait --> $DIR/deriving-all-codegen.rs:80:24 | LL | #[derive(Debug, Hash)] | ----- in this derive macro expansion LL | #[repr(packed)] LL | struct PackedUnsizedU8([u8]); | ^^^^ | = 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 #107457 = help: consider implementing the trait by hand, or remove the `packed` attribute = note: `#[warn(byte_slice_in_packed_struct_with_derive)]` on by default = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info) warning: byte slice in a packed struct that derives a built-in trait --> $DIR/deriving-all-codegen.rs:80:24 | LL | #[derive(Debug, Hash)] | ---- in this derive macro expansion LL | #[repr(packed)] LL | struct PackedUnsizedU8([u8]); | ^^^^ | = 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 #107457 = help: consider implementing the trait by hand, or remove the `packed` attribute = note: this warning originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info) warning: 2 warnings emitted Future incompatibility report: Future breakage diagnostic: warning: byte slice in a packed struct that derives a built-in trait --> $DIR/deriving-all-codegen.rs:80:24 | LL | #[derive(Debug, Hash)] | ----- in this derive macro expansion LL | #[repr(packed)] LL | struct PackedUnsizedU8([u8]); | ^^^^ | = 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 #107457 = help: consider implementing the trait by hand, or remove the `packed` attribute = note: `#[warn(byte_slice_in_packed_struct_with_derive)]` on by default = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info) Future breakage diagnostic: warning: byte slice in a packed struct that derives a built-in trait --> $DIR/deriving-all-codegen.rs:80:24 | LL | #[derive(Debug, Hash)] | ---- in this derive macro expansion LL | #[repr(packed)] LL | struct PackedUnsizedU8([u8]); | ^^^^ | = 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 #107457 = help: consider implementing the trait by hand, or remove the `packed` attribute = note: `#[warn(byte_slice_in_packed_struct_with_derive)]` on by default = note: this warning originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)