No Result with stack trace

[nmrao]

Just installed cargo / rust and following commands.
Using ubuntu 20.04

└──| oi "teach me awk commands"
No result: Perhaps one of these links might help?
thread 'main' panicked at src/main.rs:276:22:
called Option::unwrap() on a None value
stack backtrace:
note: Some details are omitted, run with RUST_BACKTRACE=full for a verbose backtrace.

Many times getting above.