[perl #127440] Segmentation Fault with Crust

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# New Ticket Created by  Daisuke Maki 
# Please include the string:  [perl #127440]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=127440 >


Putting load against Crust produces a segmentation fault.
Error:

=begin

PERL6LIB=lib ./bin/crustup app.p6sgi 
http server is ready: http://127.0.0.1:5000/ (pid:50723)
zsh: segmentation fault  PERL6LIB=lib ./bin/crustup app.p6sgi

=end

to reproduce (on OS X, Yosemite)

=begin

brew install wrk

rakudobrew build moar
rakudobrew build panda
git clone g...@github.com:tokuhirom/p6-Crust.git
cd p6-Crust
panda installdeps .

cat <<EOM>app.p6sgi
use v6;

sub (%env) {
    return (200, ["Content-Type" => "text/plain"], ["Hello, World!\n"])
};
EOM

PERL6LIB=lib ./bin/crustapp app.p6sgi

wrk -c 400 https://127.0.0.1:5000/

=end

perl6 version:

=begin

perl6 -v
This is Rakudo version 2015.12-230-g2e17820 built on MoarVM version 
2015.12-29-g8079ca5
implementing Perl 6.c.

=end