1 error: Undefined Behavior: reading memory at ALLOC[0x0..0x10], but memory is uninitialized at [0x4..0x10], and this operation requires initialized memory
2 --> RUSTLIB/core/src/slice/cmp.rs:LL:CC
4 LL | let mut order = unsafe { memcmp(left.as_ptr(), right.as_ptr(), len) as isize };
5 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ reading memory at ALLOC[0x0..0x10], but memory is uninitialized at [0x4..0x10], and this operation requires initialized memory
7 = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
8 = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
10 = note: inside `<u8 as core::slice::cmp::SliceOrd>::compare` at RUSTLIB/core/src/slice/cmp.rs:LL:CC
11 = note: inside `core::slice::cmp::<impl std::cmp::Ord for [u8]>::cmp` at RUSTLIB/core/src/slice/cmp.rs:LL:CC
12 note: inside `main` at $DIR/uninit_buffer.rs:LL:CC
13 --> $DIR/uninit_buffer.rs:LL:CC
15 LL | drop(slice1.cmp(slice2));
18 note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
20 Uninitialized memory occurred at ALLOC[0x4..0x10], in this allocation:
21 ALLOC (Rust heap, size: 32, align: 8) {
22 0x00 │ 41 42 43 44 __ __ __ __ __ __ __ __ __ __ __ __ │ ABCD░░░░░░░░░░░░
23 0x10 │ 00 __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ │ .░░░░░░░░░░░░░░░
26 error: aborting due to previous error