From @usev6

The following code started to fail on rakudo-j with Rakudo commit 069b789af5​:

$ perl6-j -e 'my @​a; @​a[0 ; 1] = "foo"; say @​a.perl'
java.lang.RuntimeException​: No such attribute '$!default' for this object
  in block <unit> at -e line 1

$ perl6-j --ll-exception -e 'my @​a; @​a[0 ; 1] = "foo"; say @​a.perl'
java.lang.RuntimeException​: No such attribute '$!default' for this object
  in pull-one (gen/jvm/CORE.setting​:16150)
  in pull-one (gen/jvm/CORE.setting​:4100)
  in push-all (gen/jvm/CORE.setting​:2389)
  in push-until-lazy (gen/jvm/CORE.setting​:2401)
  in reify-until-lazy (gen/jvm/CORE.setting​:14287)
  in join (gen/jvm/CORE.setting​:15074)
  in join (gen/jvm/CORE.setting​:1799)
  in (gen/jvm/CORE.setting​:16841)
  in (gen/jvm/CORE.setting​:1161)
  in (gen/jvm/CORE.setting​:1157)
  in perlseen (gen/jvm/CORE.setting​:1151)
  in perl (gen/jvm/CORE.setting​:16840)
  in perl (gen/jvm/CORE.setting​:1175)
  in (gen/jvm/CORE.setting​:16843)
  in pull-one (gen/jvm/CORE.setting​:4111)
  in push-all (gen/jvm/CORE.setting​:2389)
  in push-until-lazy (gen/jvm/CORE.setting​:2401)
  in reify-until-lazy (gen/jvm/CORE.setting​:14287)
  in join (gen/jvm/CORE.setting​:15074)
  in join (gen/jvm/CORE.setting​:1799)
  in (gen/jvm/CORE.setting​:16841)
  in (gen/jvm/CORE.setting​:1161)
  in (gen/jvm/CORE.setting​:1157)
  in perlseen (gen/jvm/CORE.setting​:1151)
  in (gen/jvm/CORE.setting​:1171)
  in perlseen (gen/jvm/CORE.setting​:1151)
  in perl (gen/jvm/CORE.setting​:16840)
  in perl (gen/jvm/CORE.setting​:1175)
  in <unit> (-e​:1)
  in <unit-outer> (-e​:1)
  in eval (gen/jvm/stage2/NQPHLL.nqp​:1198)
  in eval (src/Perl6/Compiler.nqp​:171)
  in (gen/jvm/stage2/NQPHLL.nqp​:1288)
  in command_eval (gen/jvm/stage2/NQPHLL.nqp​:1285)
  in command_eval (src/Perl6/Compiler.nqp​:29)
  in command_line (gen/jvm/stage2/NQPHLL.nqp​:1269)
  in MAIN (gen/jvm/main.nqp​:37)
  in <mainline> (gen/jvm/main.nqp​:33)
  in (gen/jvm/main.nqp)

On the previous commit 99dfd47b07 it works as expected​:

$ perl6-j -e 'my @​a; @​a[0 ; 1] = "foo"; say @​a.perl'
[[Any, "foo"],]

There is a test for this in S09-subscript/multidim-assignment.t

From @usev6

As a follow-up​: The following code works as expected​:

$ perl6-j -e 'my @​a; @​a[0;1] = "foo"; @​a[0;0] = "bar"; say @​a.perl'
[["bar", "foo"],]

From @usev6

Fixed with rakudo/rakudo@13f6b63455

I'm closing this ticket as 'resolved'.

@usev6 - Status changed from 'new' to 'resolved'