From @coke

15​:06 < [Coke]> r​: use Test; throws-like 'my int $a is default(42)',
  X​::Comp​::Trait​::NotOnNative,type => 'is',subtype =>
  'default';
15​:06 <+camelia> rakudo-moar 6abf2b​: OUTPUT« 1..4␤ ok 1 - 'my int $a is
  default(42)' died␤ ok 2 - right exception type
  (X​::Comp​::Trait​::NotOnNative)␤ ok 3 - .subtype matches
  default␤ ok 4 - .type matches is␤ok 1 - did we throws-like
  X​::Comp​::Trait​::NotOnNative?␤»
15​:06 <+camelia> ..rakudo-jvm 6abf2b​: OUTPUT« 1..4␤ not ok 1 - 'my int $a
  is default(42)' died␤ ␤# Failed test ''my int $a is
  default(42)' died'␤# at /tmp/tmpfile line 1␤ ok 2 - # SKIP
  Code did not die, can not check exception␤ ok 3 - # SKIP
  Code did not die, can not check e…»--

Test in S02-names/is_default.t

Will "Coke" Coleda

This test works now (cmp. Raku/roast@b0eda67335).

I don't know when/how it was fixed, but I'll close this old ticket.