https://rt.perl.org/Public/Bug/Display.html?id=127208

gistfile1.txt

dogbert@dogbert-VirtualBox ~/repos/rakudo $ ./perl6-gdb-m -e 'my @primes = grep { .is-prime }, 1 .. *; my @p = gather for 4000, 5, 100, 2000 -> $n { take start { @primes[$n] }; }; .say for await @p;'
================================================================================================
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 2016.12.137.g.338336118 built on MoarVM version 2016.12.35.g.293.bda.71,
running on ubuntu (14.04.3.LTS.Trusty.Tahr) / linux (3.19.0.32.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=/home/dogbert/repos/rakudo/install/share/nqp/lib --libpath=/home/dogbert/repos/rakudo/install/share/nqp/lib --libpath=. /home/dogbert/repos/rakudo/perl6.moarvm --nqp-lib=blib -e my\ @primes\ =\ grep\ \{\ .is-prime\ \},\ 1\ ..\ \*\;\ my\ @p\ =\ gather\ for\ 4000,\ 5,\ 100,\ 2000\ -\>\ \$n\ \{\ take\ start\ \{\ @primes\[\$n\]\ \}\;\ \}\;\ .say\ for\ await\ @p\;
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".
Starting program: /home/dogbert/repos/rakudo/install/bin/moar --execname=./perl6-gdb-m --libpath=/home/dogbert/repos/rakudo/install/share/nqp/lib --libpath=/home/dogbert/repos/rakudo/install/share/nqp/lib --libpath=. /home/dogbert/repos/rakudo/perl6.moarvm --nqp-lib=blib -e my\ @primes\ =\ grep\ \{\ .is-prime\ \},\ 1\ ..\ \*\;\ my\ @p\ =\ gather\ for\ 4000,\ 5,\ 100,\ 2000\ -\>\ \$n\ \{\ take\ start\ \{\ @primes\[\$n\]\ \}\;\ \}\;\ .say\ for\ await\ @p\;
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".
[New Thread 0xb657eb40 (LWP 21634)]
[New Thread 0xb5bffb40 (LWP 21635)]
[New Thread 0xb53feb40 (LWP 21636)]
[New Thread 0xb47ffb40 (LWP 21637)]
*** Error in `/home/dogbert/repos/rakudo/install/bin/moar': realloc(): invalid old size: 0xb4a2d680 ***

Program received signal SIGABRT, Aborted.
[Switching to Thread 0xb47ffb40 (LWP 21637)]
0xb7fdccb0 in ?? ()
(gdb) bt
#0  0xb7fdccb0 in ?? ()
#1  0xb7a364ba in malloc_printerr (action=<optimized out>, str=0xb7b248fd "realloc(): invalid old size", ptr=0xb4a2d680) at malloc.c:4996
#2  0xb7a3909c in _int_realloc (av=av@entry=0xb4a00010, oldp=oldp@entry=0xb4a2d678, oldsize=oldsize@entry=40, nb=nb@entry=72) at malloc.c:4234
#3  0xb7a39f69 in __GI___libc_realloc (oldmem=0xb4a2d680, bytes=64) at malloc.c:3029
#4  0xb7c96b70 in MVM_realloc (p=0xb4a2d680, size=64) at src/core/alloc.h:20
#5  0xb7c97e78 in set_size_internal (tc=0x9df6b90, body=0x804d2c8, n=9, repr_data=0x93969f8) at src/6model/reprs/MVMArray.c:334
#6  0xb7c9852a in push (tc=0x9df6b90, st=0x9363368, root=0x804d2b8, data=0x804d2c8, value=..., kind=8) at src/6model/reprs/MVMArray.c:437
#7  0xb7c28f4d in MVM_interp_run (tc=0x9df6b90, initial_invoke=0xb7c59347 <thread_initial_invoke>, invoke_data=0x9df5188) at src/core/interp.c:2194
#8  0xb7c59489 in start_thread (data=0x9df5188) at src/core/threads.c:77
#9  0xb7d4af47 in uv.thread_start () from //home/dogbert/repos/rakudo/install/lib/libmoar.so
#10 0xb7966f72 in start_thread (arg=0xb47ffb40) at pthread_create.c:312
#11 0xb7aaef8e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:129
(gdb) frame 5
#5  0xb7c97e78 in set_size_internal (tc=0x9df6b90, body=0x804d2c8, n=9, repr_data=0x93969f8) at src/6model/reprs/MVMArray.c:334
334	            : MVM_malloc(ssize * repr_data->elem_size);
(gdb) p MVM_dump_backtrace(tc)
   at <unknown>:1  (./CORE.setting.moarvm:push)
 from SETTING::src/core/Iterator.pm:31  (./CORE.setting.moarvm:push-exactly)
 from SETTING::src/core/Iterator.pm:50  (./CORE.setting.moarvm:push-at-least)
 from SETTING::src/core/List.pm:183  (./CORE.setting.moarvm:reify-at-least)
 from SETTING::src/core/List.pm:674  (./CORE.setting.moarvm:pull-one)
 from SETTING::src/core/Iterator.pm:31  (./CORE.setting.moarvm:push-exactly)
 from SETTING::src/core/Iterator.pm:50  (./CORE.setting.moarvm:push-at-least)
 from SETTING::src/core/List.pm:183  (./CORE.setting.moarvm:reify-at-least)
 from SETTING::src/core/List.pm:674  (./CORE.setting.moarvm:pull-one)
 from SETTING::src/core/Iterator.pm:31  (./CORE.setting.moarvm:push-exactly)
 from SETTING::src/core/Iterator.pm:50  (./CORE.setting.moarvm:push-at-least)
 from SETTING::src/core/List.pm:183  (./CORE.setting.moarvm:reify-at-least)
 from SETTING::src/core/List.pm:674  (./CORE.setting.moarvm:pull-one)
 from SETTING::src/core/Any-iterable-methods.pm:928  (./CORE.setting.moarvm:pull-one)
 from SETTING::src/core/Iterator.pm:31  (./CORE.setting.moarvm:push-exactly)
 from SETTING::src/core/Iterable.pm:97  (./CORE.setting.moarvm:push-exactly)
 from SETTING::src/core/Iterator.pm:50  (./CORE.setting.moarvm:push-at-least)
 from SETTING::src/core/List.pm:183  (./CORE.setting.moarvm:reify-at-least)
 from SETTING::src/core/Array.pm:354  (./CORE.setting.moarvm:AT-POS)
 from SETTING::src/core/array_slice.pm:129  (./CORE.setting.moarvm:postcircumfix:<[ ]>)
 from -e:1  (<ephemeral file>:)
 from SETTING::src/core/Promise.pm:175  (./CORE.setting.moarvm:)
 from SETTING::src/core/ThreadPoolScheduler.pm:162  (./CORE.setting.moarvm:)
 from SETTING::src/core/ThreadPoolScheduler.pm:51  (./CORE.setting.moarvm:)
 from SETTING::src/core/ThreadPoolScheduler.pm:44  (./CORE.setting.moarvm:)
 from SETTING::src/core/ThreadPoolScheduler.pm:41  (./CORE.setting.moarvm:)
 from SETTING::src/core/Thread.pm:30  (./CORE.setting.moarvm:THREAD-ENTRY)
$1 = void