Can't achieve the given example

[ChandelierX]

No matter whether I use cargo build or sudo make install, when I call echo 'fee fi fo fum' | retest 'f\w\w' or retest '\w+\s' --subject 'fee fi fo fum', I get the same error like below:

thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', libcore/option.rs:335:21
note: Run with `RUST_BACKTRACE=1` for a backtrace.

The install process itself gives me:

warning: unused import: `Terminal`
 --> src/retest.rs:4:25
  |
4 | use term::{self, color, Terminal};
  |                         ^^^^^^^^
  |
  = note: #[warn(unused_imports)] on by default

    Finished release [optimized] target(s) in 122.51 secs
Installing to //usr/local/bin...
install -m 0755 target/release/retest //usr/local/bin

Because I don't know anything about Rust, could you please do me a favor? I really want to use this useful CLI tool for regex test.
Besides, I have

------------------------
 OS: Manjaro Linux x86_64
 Host: ThinkPad Edge E540
 Kernel: 4.14.34-1-MANJARO
 Shell: zsh 5.5.1
 DE: KDE
 WM: KWin
 Terminal: Konsole

[sagebind]

Thanks for this bug report! I'll look into this as soon as I can.

@ChandelierX Could you re-run the example with the RUST_BACKTRACE environment variable set, and then post the backtrace? That would help me debug.

export RUST_BACKTRACE=1
retest '\w+\s' --subject 'fee fi fo fum'

[ChandelierX]

Of course I'd like to post the backtrace. The following snippet is the output:

export RUST_BACKTRACE=1
retest '\w+\s' --subject 'fee fi fo fum'
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', libcore/option.rs:335:21
stack backtrace:
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
   1: std::sys_common::backtrace::_print
   2: std::panicking::default_hook::{{closure}}
   3: std::panicking::default_hook
   4: std::panicking::rust_panic_with_hook
   5: std::panicking::begin_panic
   6: std::panicking::begin_panic_fmt
   7: rust_begin_unwind
   8: core::panicking::panic_fmt
   9: core::panicking::panic
  10: retest::retest::print_match
  11: retest::retest::print_subject_highlighted
  12: retest::main
  13: std::rt::lang_start::{{closure}}
  14: std::panicking::try::do_call
  15: __rust_maybe_catch_panic
  16: std::rt::lang_start_internal
  17: main
  18: __libc_start_main
  19: _start

I can't figure out what's wrong with it. And sorry for the delayed reply.

[sagebind]

Thanks, that helped me identify the issue. Oddly, it seems that the program crashes when it tries to write color escape codes to your terminal. Perhaps it could not load the terminfo database? Try installing ncurses and try again.

For the future, I will update the code to fail more gracefully and print an error message in this situation.

[sagebind]

@ChandelierX The latest version (0.2.3) now prints an error message when this happens giving a hint to the problem.

[ChandelierX]

@sagebind The good news is: now it works well in both konsole and xTerm of mine.
I'd better mention some weird facts:

1. ncurses is in my computer since the very beginning. Therefore it's unlikely the main reason.
2. I found it originally works well in xterm (even before I did anything like update retest), but not in konsole.
3. After I updated it to your newest version (by sudo make install), it works well in both of them.

[sagebind]

I did update my dependencies, so perhaps that pulled in an upstream bugfix. I'm glad it is working now!