From @tadzik

Tested on Rakudo 2014.08.

  tadzik | r​: my $a = buf8.new([]); say "Foo​: $a" # this is amusing
  +camelia | rakudo-jvm c793d8​: OUTPUT«java.lang.StackOverflowErrorâ�¤â�¤Â»
  +camelia | ..rakudo-parrot c793d8​: OUTPUT«maximum recursion depth
exceeded�current
  | instr.​: 'print_exception' pc 142392
(src/gen/p-CORE.setting.pir​:61408)
  | (gen/parrot/CORE.setting​:11718)â�¤called from Sub 'Stringy'
pc 233104
  | (src/gen/p-CORE.setting.pir​:96775)
(gen/parrot/CORE.setting​:1038)â�¤caâ�¦Â»
  +camelia | ..rakudo-moar c793d8​: OUTPUT«(signal )»
  masak | o.O
  masak | tadzik​: please submit that.
  tadzik | I think concat is the problem
  tadzik | r​: my $a = buf8.new([]); say $a
  +camelia | rakudo-{parrot,jvm,moar} c793d8​: OUTPUT«Buf​:0x<>â�¤Â»
  tadzik | r​: my $a = buf8.new([]); say "" ~ $a
  tadzik | . o O ( BOOM )
  +camelia | rakudo-jvm c793d8​: OUTPUT«java.lang.RuntimeException​:
  | java.lang.StackOverflowErrorâ�¤â�¤Â»
  +camelia | ..rakudo-parrot c793d8​: OUTPUT«maximum recursion depth
exceeded�current
  | instr.​: 'print_exception' pc 142392
(src/gen/p-CORE.setting.pir​:61408)
  | (gen/parrot/CORE.setting​:11718)â�¤called from Sub 'Stringy'
pc 233104
  | (src/gen/p-CORE.setting.pir​:96775)
(gen/parrot/CORE.setting​:1038)â�¤caâ�¦Â»
  +camelia | ..rakudo-moar c793d8​: OUTPUT«(signal )»
  tadzik | r​: my $a = buf8.new([]); say ~$a
  +camelia | rakudo-{parrot,jvm,moar} c793d8​: OUTPUT«Buf​:0x<>â�¤Â»
  masak | some dispatch somewhere self-calls and goes into an
infinite loop.
  tadzik | it would seem so, yes

From @timo

On 23/08/14 13​:44, Tadeusz SoÅ�nierz (via RT) wrote​:

# New Ticket Created by Tadeusz So�nierz
# Please include the string​: [perl #​122600]
# in the subject line of all future correspondence about this issue.
# <URL​: https://rt-archive.perl.org/perl6/Ticket/Display.html?id=122600 >

Tested on Rakudo 2014.08.

 tadzik | r​: my $a = buf8\.new\(\[\]\); say "Foo​: $a" \# this is amusing

+camelia | rakudo-jvm c793d8​: OUTPUT«java.lang.StackOverflowErrorâ�¤â�¤Â»
+camelia | ..rakudo-parrot c793d8​: OUTPUT«maximum recursion depth
exceeded�current
| instr.​: 'print_exception' pc 142392
(src/gen/p-CORE.setting.pir​:61408)
| (gen/parrot/CORE.setting​:11718)â�¤called from Sub 'Stringy'
pc 233104
| (src/gen/p-CORE.setting.pir​:96775)
(gen/parrot/CORE.setting​:1038)â�¤caâ�¦Â»
+camelia | ..rakudo-moar c793d8​: OUTPUT«(signal )»
masak | o.O
masak | tadzik​: please submit that.
tadzik | I think concat is the problem
tadzik | r​: my $a = buf8.new([]); say $a
+camelia | rakudo-{parrot,jvm,moar} c793d8​: OUTPUT«Buf​:0x<>â�¤Â»
tadzik | r​: my $a = buf8.new([]); say "" ~ $a
tadzik | . o O ( BOOM )
+camelia | rakudo-jvm c793d8​: OUTPUT«java.lang.RuntimeException​:
| java.lang.StackOverflowError��»
+camelia | ..rakudo-parrot c793d8​: OUTPUT«maximum recursion depth
exceeded�current
| instr.​: 'print_exception' pc 142392
(src/gen/p-CORE.setting.pir​:61408)
| (gen/parrot/CORE.setting​:11718)â�¤called from Sub 'Stringy'
pc 233104
| (src/gen/p-CORE.setting.pir​:96775)
(gen/parrot/CORE.setting​:1038)â�¤caâ�¦Â»
+camelia | ..rakudo-moar c793d8​: OUTPUT«(signal )»
tadzik | r​: my $a = buf8.new([]); say ~$a
+camelia | rakudo-{parrot,jvm,moar} c793d8​: OUTPUT«Buf​:0x<>â�¤Â»
masak | some dispatch somewhere self-calls and goes into an
infinite loop.
tadzik | it would seem so, yes
Aye, Buf.Stringy will return self.

This has annoyed me at least once before.

The RT System itself - Status changed from 'new' to 'open'

From @FROGGS

Patch​: rakudo/rakudo@2121b16c03
Tests​: Raku/roast@fcf5aff5c9

@FROGGS - Status changed from 'open' to 'resolved'