`dust -h` panics when stdout is closed

[lopopolo]

$ RUST_BACKTRACE=1 dust -h | false
thread 'main' panicked at 'Error writing Error to stdout: Os { code: 32, kind: BrokenPipe, message: "Broken pipe" }', /Users/brew/Library/Caches/Homebrew/cargo_cache/registry/src/github.com-1ecc6299db9ec823/clap-2.33.3/src/errors.rs:401:55
stack backtrace:
   0: _rust_begin_unwind
   1: core::panicking::panic_fmt
   2: core::result::unwrap_failed
   3: core::result::Result<T,E>::expect
   4: clap::errors::Error::exit
   5: clap::app::App::get_matches_from::{{closure}}
   6: clap::app::App::get_matches
   7: dust::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
$ dust --version
Dust 0.7.5

Clap provides a get_matches_from_safe API that returns a Result rather than panicking when failing to write to stdout.

Here's some MIT-licensed code I use in one of my projects that does this dance in a panic-free way:

https://github.com/artichoke/artichoke/blob/d527412f9438aeba4cadb1f4303237f6f9e0cd4d/src/bin/artichoke.rs#L138-L173

[lopopolo]

I've opened up this ticket with upstream clap to see if the maintainers are open to fixing this panic on the v2 branch:

• Consider releasing a patch to the v2 release line that addresses a panic that is widespread across the ecosystem clap-rs/clap#3055

[bootandy]

From that thread:
v2.33.4 has been released that fixes this panic

[bootandy]

I have moved to Clap 3, this should solve this.