rakudo compilation bug

gistfile1.txt

$ perl6 -Ilib -MM42::PASM::Backends -e 'say M42::PASM::Backend::.perl'
("GNUC" => M42::PASM::Backend::GNUC).hash

$ rm $(find lib -name '*.pbc')

$ perl6 -Ilib -MM42::PASM::Backends -e 'say M42::PASM::Backend::.perl'
("GNUC" => M42::PASM::Backend::GNUC).hash

$ rm $(find lib -name '*.pir')

$ perl6 -Ilib -MM42::PASM::Backends -e 'say M42::PASM::Backend::.perl'
("AST" => M42::PASM::Backend::AST, "ASG" => M42::PASM::Backend::ASG, "GNUC" => M42::PASM::Backend::GNUC).hash

$ cat lib/M42/PASM/Backends.pm
use v6;
use M42::PASM::Backend::AST;
use M42::PASM::Backend::ASG;
use M42::PASM::Backend::GNUC;

$ head lib/M42/PASM/Backend/AST.pm
use v6;
use M42::Compiler;
use M42::Dumper;
use M42::PASM::Grammar;
use M42::PASM::Parser;

class M42::PASM::Backend::AST {
        also does M42::Compiler;
        also does M42::Dumper;


$ head lib/M42/PASM/Backend/ASG.pm
use v6;
use pretty;
use M42::Compiler;
use M42::PASM::Composer;

class M42::PASM::Backend::ASG {
        also does M42::Compiler;

        has $.indent = '  ';
        has $.grammar = M42::PASM::Grammar;

$ head lib/M42/PASM/Backend/GNUC.pm
use v6;
use M42::Compiler;
use M42::PASM::Grammar;
use M42::PASM::Composer;

class M42::PASM::Backend::GNUC {
        also does M42::Compiler;

        has $.grammar = M42::PASM::Grammar;
        has $.parser = M42::PASM::Composer.new;