It appears we can golf this down further:
m: class A { method foo { return 42 } }; my $a = A.new; for ^157 { $a.foo } # still smaller golf, no attributes neede rakudo-moar 87e91c: ( no output ) m: class A { method foo { return 42 } }; my $a = A.new; for ^158 { $a.foo } # at 158 it fails rakudo-moar 87e91c: OUTPUT«Attempt to return outside of any Routine in block <unit> at /tmp/OZc4EqaZLv line 1» m: sub foo() { return 42 }; for ^157 { foo } # still smaller golf rakudo-moar 87e91c: ( no output ) m: sub foo() { return 42 }; for ^158 { foo } # fails at 158 rakudo-moar 87e91c: OUTPUT«Attempt to return outside of any Routine in block <unit> at /tmp/tOCcim2lY1 line 1» Of course, if there had been a Routine outside, this error would have been silent! Just done the wrong thing!