error[E0080]: it is undefined behavior to use this value --> $DIR/union-ice.rs:13:1 | LL | const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR it is undefined behavior to use this value | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized bytes, but expected initialized plain (non-pointer) bytes | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error[E0080]: it is undefined behavior to use this value --> $DIR/union-ice.rs:15:1 | LL | / const FIELD_PATH: Struct = Struct { //~ ERROR it is undefined behavior to use this value LL | | a: 42, LL | | b: unsafe { UNION.field3 }, LL | | }; | |__^ type validation failed: encountered uninitialized bytes at .b, but expected initialized plain (non-pointer) bytes | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error[E0080]: it is undefined behavior to use this value --> $DIR/union-ice.rs:25:1 | LL | / const FIELD_PATH2: Struct2 = Struct2 { //~ ERROR it is undefined behavior to use this value LL | | b: [ LL | | 21, LL | | unsafe { UNION.field3 }, ... | LL | | a: 42, LL | | }; | |__^ type validation failed: encountered undefined bytes at .b[1] | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior error: aborting due to 3 previous errors For more information about this error, try `rustc --explain E0080`.