[perl #130291] [CONC] Proc::Async sends empty trying to stderr/stdout tap on program exit, even though the program did not send anything

[Zoffix Znet via RT]

On Wed, 07 Dec 2016 07:24:04 -0800, alexander.kiryu...@gmail.com wrote:
> The original example to reproduce:
> 
> use v6;
> 
> my $p = Proc::Async.new('ls', '-l');
> 
> $p.stdout.tap(-> $v { say $v });
> $p.stderr.tap(-> $v { say $v.WHAT; say $v.perl; }); # Prints (Str) and
> empty string..
> 
> await $p.start;
> 
> Stdout and stderr is tapped with empty output on any command.

Fixed in 
https://github.com/rakudo/rakudo/commit/08ccbbbd768adf430b36180dad4640bb14eeeba0

Marking Tests Needed