NQPInteropError

use QAST:from<NQP>;

my $qast = QAST::Block.new(
    QAST::IVal.new( :value(42) )
); 
my $comp_unit = QAST::CompUnit.new(
    # Set the HLL.
    :hll('perl6'),

    # This variable contains the outermost QAST::Block of the
    # program.
    $qast,

    # If we run the program as the mainline, then call the top
    # block automatically.
    :main(QAST::Op.new(
        :op('call'),
        QAST::BVal.new( :value($qast) )
    ))
);

my $compiler = nqp::getcomp('perl6');


say $_ for $compiler.stages();

my $backend = $compiler.backend();
my $mast = $backend.mast($comp_unit);
my $compiled = $backend.mbc($mast);
$compiled();

say "Compiled and ran with no errors.";