[perl #131888] No such method 'cache' for invocant of type 'NQPMu'

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# New Ticket Created by  Evan Miller 
# Please include the string:  [perl #131888]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=131888 >


I'm using the Rakudo nom and MoarVM master. A call to "await" on an array
of Promises is failing with the error:

        No such method 'cache' for invocant of type 'NQPMu'
          in any  at
/Users/emiller/Code/rakudo/install/share/perl6/runtime/CORE.d.setting.moarvm
line 1

The full error can be seen here:

  https://github.com/scmorrison/uzu/issues/10#issuecomment-321975611

The failing call to "await" is here:


https://github.com/scmorrison/uzu/blob/8d619bb682992baaf07c84262898b29f4e6c3fe6/lib/Uzu/Render.pm6#L401

I'm running a version of that source file with "use v6.d.PREVIEW". Here's
the output from perl6 --version:

  This is Rakudo version 2017.07-148-g5fcce6732 built on MoarVM version
2017.07-382-g348b4262
  implementing Perl 6.c.