[perl #131026] Failing to read from IO::Pipe fast enough, apparently loses data

[via RT]

# New Ticket Created by  Zoffix Znet 
# Please include the string:  [perl #131026]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=131026 >


  zoffix@VirtualBox:~$ perl6 -e '$ = shell(:out, "yes | head -n 
100000").out.lines'
  head: write error: Connection reset by peer
  head: write error
  zoffix@VirtualBox:~$ perl6 -e '$ = shell(:out, "yes | head -n 
100000").out.IO::Handle::lines'                                                 
                                                                                
                                 
  zoffix@VirtualBox:~$ perl6 -e '$ = shell(:out, "yes | head -n 
100000").out.IO::Handle::lines'
  head: write error: Connection reset by peer
  head: write error

This is Rakudo version 2017.02-186-g9da6de4 built on MoarVM version 
2017.02-18-g5f9d698
implementing Perl 6.c.

Note that the same error doesn't happen with head -n 60000, suggesting it's 
some sort of buffer sized to 65536. Adjusting RAKUDO_DEFAULT_READ_ELEMS doesn't 
solve it.

Unsure if this is meant to be this way or not. I'd expect no write errors to 
happen or for Perl 6 to complain about it. If this is normal, then at least it 
should be documented as a caveat.