thread 'main' panicked at 'panicking from libstd', $DIR/panic1.rs:LL:CC
stack backtrace:
   0: std::rt::begin_panic
 at RUSTLIB/std/src/panicking.rs:LL:CC
   1: main
 at $DIR/panic1.rs:LL:CC
   2: <fn() as std::ops::FnOnce<()>>::call_once - shim(fn())
 at RUSTLIB/core/src/ops/function.rs:LL:CC
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.