backtrace.rs

thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', ../src/libcore/option.rs:323
stack backtrace:
   1:     0x55e4e99bd5ff - std::sys::backtrace::tracing::imp::write::h6f1d53a70916b90d
   2:     0x55e4e99c00ad - std::panicking::default_hook::{{closure}}::h137e876f7d3b5850
   3:     0x55e4e99bf60a - std::panicking::default_hook::h0ac3811ec7cee78c
   4:     0x55e4e99bfb58 - std::panicking::rust_panic_with_hook::hc303199e04562edf
   5:     0x55e4e99bf9f2 - std::panicking::begin_panic::h6ed03353807cf54d
   6:     0x55e4e99bf930 - std::panicking::begin_panic_fmt::hc321cece241bb2f5
   7:     0x55e4e99bf8b1 - rust_begin_unwind
   8:     0x55e4e99f4b1f - core::panicking::panic_fmt::h27224b181f9f037f
   9:     0x55e4e99f4a4b - core::panicking::panic::h53676c30b3bd95eb
  10:     0x55e4e99b7915 - <core::option::Option<T>>::unwrap::hfa992e33cf13fd06
                        at /buildslave/rust-buildbot/slave/stable-dist-rustc-linux/build/obj/../src/libcore/macros.rs:21
  11:     0x55e4e99b7aa9 - rust_out::main::hb497928495d48c40
                        at /tmp/<anon>:6
  12:     0x55e4e99c7b76 - __rust_maybe_catch_panic
  13:     0x55e4e99bee81 - std::rt::lang_start::h538f8960e7644c80
  14:     0x55e4e99b7b73 - main
  15:     0x7f9c8748582f - __libc_start_main
  16:     0x55e4e99b7798 - _start
  17:                0x0 - <unknown>