Thread 1 starting, will block on mutex
Thread 1 reported it has started

thread '<unnamed>' ($TID) panicked at tests/pass/panic/concurrent-panic.rs:LL:CC:
panic in thread 2
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
Thread 2 blocking on thread 1
Thread 2 reported it has started
Unlocking mutex

thread '<unnamed>' ($TID) panicked at tests/pass/panic/concurrent-panic.rs:LL:CC:
panic in thread 1
Thread 1 has exited
Thread 2 has exited