thread 'main' panicked at 'debug!!!', $DIR/short-ice-remove-middle-frames.rs:52:5 stack backtrace: 0: std::panicking::begin_panic 1: short_ice_remove_middle_frames::seven 2: short_ice_remove_middle_frames::sixth 3: short_ice_remove_middle_frames::fifth::{{closure}} 4: short_ice_remove_middle_frames::second 5: short_ice_remove_middle_frames::first::{{closure}} 6: short_ice_remove_middle_frames::first 7: short_ice_remove_middle_frames::main 8: core::ops::function::FnOnce::call_once note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.