error: Undefined Behavior: Data race detected between (1) Write on thread `<unnamed>` and (2) Read on thread `<unnamed>` at ALLOC. (1) just happened here
  --> $DIR/read_write_race.rs:LL:CC
   |
LL |             *c.0 = 64;
   |             ^^^^^^^^^ Data race detected between (1) Write on thread `<unnamed>` and (2) Read on thread `<unnamed>` at ALLOC. (1) just happened here
   |
help: and (2) occurred earlier here
  --> $DIR/read_write_race.rs:LL:CC
   |
LL |             let _val = *c.0;
   |                        ^^^^
   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
   = note: BACKTRACE (of the first span):
   = note: inside closure at $DIR/read_write_race.rs:LL:CC

note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

error: aborting due to previous error