DU fail

gistfile1.txt

dogbert@dogbert-VirtualBox ~/repos/rakudo $ ./perl6-gdb-m t/spec/S02-literals/quoting.t
================================================================================================
This is Rakudo Perl 6 running in the GNU debugger, which often allows the user to generate useful back-
traces to debug or report issues in Rakudo, the MoarVM backend or the currently running code.

This Rakudo version is 2018.08.84.g.78.bebc.7 built on MoarVM version 2018.08.46.gfb.8976.a,
running on linuxmint (18.3.Sylvia) / linux (4.10.0.38.generic)

Type `bt full` to generate a backtrace if applicable, type `q` to quit or `help` for help.
------------------------------------------------------------------------------------------------
Reading symbols from /home/dogbert/repos/rakudo/install/bin/moar...done.
Starting program: /home/dogbert/repos/rakudo/install/bin/moar --execname=./perl6-gdb-m --libpath=. --libpath=blib --libpath=/home/dogbert/repos/rakudo/install/share/nqp/lib --libpath=/home/dogbert/repos/rakudo/install/share/nqp/lib --libpath=/home/dogbert/repos/rakudo/install/share/nqp/lib /home/dogbert/repos/rakudo/perl6.moarvm --nqp-lib=blib t/spec/S02-literals/quoting.t
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7ffff633f700 (LWP 2632)]
MoarVM oops: Malformed DU chain: reading sp_getspeshslot of 6(1) not in graph
Spesh of '' (cuid: 110, file: gen/moar/BOOTSTRAP.nqp:2186)
Callsite 0x7ffff7d293a0 (1 args, 1 pos)
Positional flags: obj

  BB 0 (0x7fffec6d3e00):
    line: 2186 (pc 0)
    Instructions:
      no_op           
    Successors: 1
    Predecessors: 
    Dominance children: 1

  BB 1 (0x7fffec6d3e88):
    line: 2186 (pc 0)
    Instructions:
      sp_getarg_o       r0(2), liti16(0)
      [Annotation: INS Deopt One (idx 0 -> pc 20; line 2187)]
      [Annotation: Logged (bytecode offset 14)]
      [Annotation: Line Number: gen/moar/BOOTSTRAP.nqp:2186]
      set               r3(2),   r0(2)
    Successors: 2
    Predecessors: 0
    Dominance children: 2

  BB 2 (0x7fffec6d3ee8):
    line: 2187 (pc 20)
    Instructions:
      set               r1(2),   r3(2)
      wval              r3(3), liti16(0), liti16(31) (P6opaque: Routine)
      [Annotation: INS Deopt One (idx 1 -> pc 48; line 2188)]
      [Annotation: Logged (bytecode offset 34)]
      sp_p6ogetvc_o     r4(2),   r1(2), liti16(48), sslot(1)
      set               r2(2),   r4(2)
      [Annotation: Logged (bytecode offset 54)]
      sp_decont         r4(5),   r2(2)
    Successors: 3
    Predecessors: 1
    Dominance children: 3

  BB 3 (0x7fffec6d3f48):
    line: 2189 (pc 60)
    Instructions:
      [Annotation: INS Deopt One (idx 2 -> pc 60; line 2189)]
      sp_guardtype      r4(3),   r4(5), sslot(0), litui32(60)
      const_i64_16      r5(1), liti16(0)
      const_s           r6(1), lits(perl6)
      sp_getspeshslot   r4(4), sslot(2)
      return_o          r4(4)
    Successors: 
    Predecessors: 2
    Dominance children: 


Facts:
      r0(0): usages=0, flags=0    
      r0(1): usages=0, flags=0     DeadWriter
      r0(2): usages=1, flags=13    KnTyp Dcntd Concr

      r1(0): usages=0, flags=0    
      r1(1): usages=0, flags=0     DeadWriter
      r1(2): usages=1, flags=13    KnTyp Dcntd Concr

      r2(0): usages=0, flags=0    
      r2(1): usages=0, flags=0     DeadWriter
      r2(2): usages=1, flags=0    

      r3(0): usages=0, flags=0    
      r3(1): usages=0, flags=0     DeadWriter
      r3(2): usages=1, deopt=0, flags=13    KnTyp Dcntd Concr
      r3(3): usages=0, flags=23    KnTyp KnVal Dcntd TyObj

      r4(0): usages=0, flags=0    
      r4(1): usages=0, flags=0     DeadWriter
      r4(2): usages=1, deopt=1, flags=0    
      r4(3): usages=0, deopt=2, flags=277   KnTyp Dcntd TyObj LogGd
      r4(4): usages=1, flags=259   KnTyp KnVal LogGd
      r4(5): usages=1, flags=4     Dcntd

      r5(0): usages=0, flags=0    
      r5(1): usages=0, flags=258   KnVal LogGd

      r6(0): usages=0, flags=0    
      r6(1): usages=1, flags=2     KnVal


Spesh slots:
    0 = STable (List)
    1 = Instance (Scalar)
    2 = Instance (Bool)

Frame size: 126 bytes


[Thread 0x7ffff633f700 (LWP 2632) exited]
[Inferior 1 (process 2628) exited with code 01]
(gdb)