1 error: Undefined Behavior: attempting a read access using <TAG> at ALLOC[0x0], but that tag does not exist in the borrow stack for this location
2 --> $DIR/illegal_read1.rs:LL:CC
4 LL | let _val = *xref; // ...but any use of raw will invalidate our ref.
7 | attempting a read access using <TAG> at ALLOC[0x0], but that tag does not exist in the borrow stack for this location
8 | this error occurs as part of an access at ALLOC[0x0..0x4]
10 = help: this indicates a potential bug in the program: it performed an invalid operation, but the Stacked Borrows rules it violated are still experimental
11 = help: see https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/stacked-borrows.md for further information
12 help: <TAG> was created by a Unique retag at offsets [0x0..0x4]
13 --> $DIR/illegal_read1.rs:LL:CC
15 LL | let xref = unsafe { &mut *xraw }; // derived from raw, so using raw is still ok...
17 help: <TAG> was later invalidated at offsets [0x0..0x4] by a read access
18 --> $DIR/illegal_read1.rs:LL:CC
20 LL | let _val = unsafe { *xraw };
23 = note: inside `main` at $DIR/illegal_read1.rs:LL:CC
25 note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
27 error: aborting due to previous error