From @mscha

  use NativeCall;

  my CArray[uint8] $a .= new(200 xx 16);
  say $a[0]; # expected output​: 200, actual output​: -56

Using Rakudo Star 2016.11​:
This is Rakudo version 2016.11 built on MoarVM version 2016.11
implementing Perl 6.c.

From @dwarring

A todo test has been added to Rakudo rakudo/rakudo@5cdea61

On Mon, 05 Dec 2016 04​:16​:56 -0800, perl6@​mscha.org wrote​:

 use NativeCall;

 my CArray\[uint8\] $a \.= new\(200 xx 16\);
 say $a\[0\];    \# expected output​: 200, actual output​: \-56

Using Rakudo Star 2016.11​:
This is Rakudo version 2016.11 built on MoarVM version 2016.11
implementing Perl 6.c.

The RT System itself - Status changed from 'new' to 'open'

Could be closed by rakudo/rakudo@ac009507a2?

@zhuomingliang Indeed, thanks for noticing!