Simpler example which borks

gistfile1.txt

dogbert@dogbert-VirtualBox ~/repos/rakudo $ cat test.pl6
await (^2).map({ start { EVAL '1 + 1' } });

dogbert@dogbert-VirtualBox ~/repos/rakudo $ ASAN_OPTIONS=detect_leaks=0 MVM_SPESH_DISABLE=1 ./perl6 --profile test.pl6
=================================================================
==5509==ERROR: AddressSanitizer: heap-use-after-free on address 0x61800007e728 at pc 0x7f4717e95c09 bp 0x7f4710e97c40 sp 0x7f4710e97c30
READ of size 8 at 0x61800007e728 thread T3
    #0 0x7f4717e95c08 in MVM_interp_run src/core/interp.c:210
    #1 0x7f4717eede35 in start_thread src/core/threads.c:87
    #2 0x7f471725e6b9 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x76b9)
    #3 0x7f471757b41c in clone (/lib/x86_64-linux-gnu/libc.so.6+0x10741c)

0x61800007e728 is located 680 bytes inside of 896-byte region [0x61800007e480,0x61800007e800)
freed by thread T3 here:
    #0 0x7f4718f9b961 in realloc (/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98961)
    #1 0x7f471805e174 in MVM_realloc src/core/alloc.h:20
    #2 0x7f471805e174 in MVM_spesh_graph_grow_deopt_table src/spesh/graph.c:42
    #3 0x7f471805e2ba in MVM_spesh_graph_add_deopt_annotation src/spesh/graph.c:61
    #4 0x7f4718062284 in build_cfg src/spesh/graph.c:366
    #5 0x7f4718066307 in MVM_spesh_graph_create src/spesh/graph.c:1231
    #6 0x7f471813b1ab in add_instrumentation src/profiler/instrument.c:233
    #7 0x7f471813b1ab in MVM_profile_instrument src/profiler/instrument.c:254
    #8 0x7f4717ece5ca in instrumentation_level_barrier src/core/frame.c:104
    #9 0x7f4717ed1b3c in MVM_frame_invoke src/core/frame.c:392
    #10 0x7f4717fbc372 in invoke_handler src/6model/reprs/MVMCode.c:10
    #11 0x7f4717e921d2 in MVM_interp_run src/core/interp.c:991
    #12 0x7f4717eede35 in start_thread src/core/threads.c:87
    #13 0x7f471725e6b9 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x76b9)

previously allocated by thread T3 here:
    #0 0x7f4718f9b961 in realloc (/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98961)
    #1 0x7f471805e174 in MVM_realloc src/core/alloc.h:20
    #2 0x7f471805e174 in MVM_spesh_graph_grow_deopt_table src/spesh/graph.c:42
    #3 0x7f471805e2ba in MVM_spesh_graph_add_deopt_annotation src/spesh/graph.c:61
    #4 0x7f4718062284 in build_cfg src/spesh/graph.c:366
    #5 0x7f4718066307 in MVM_spesh_graph_create src/spesh/graph.c:1231
    #6 0x7f471813b1ab in add_instrumentation src/profiler/instrument.c:233
    #7 0x7f471813b1ab in MVM_profile_instrument src/profiler/instrument.c:254
    #8 0x7f4717ece5ca in instrumentation_level_barrier src/core/frame.c:104
    #9 0x7f4717ed1b3c in MVM_frame_invoke src/core/frame.c:392
    #10 0x7f4717fbc372 in invoke_handler src/6model/reprs/MVMCode.c:10
    #11 0x7f4717e921d2 in MVM_interp_run src/core/interp.c:991
    #12 0x7f4717eede35 in start_thread src/core/threads.c:87
    #13 0x7f471725e6b9 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x76b9)

Thread T3 created by T2 here:
    #0 0x7f4718f39253 in pthread_create (/usr/lib/x86_64-linux-gnu/libasan.so.2+0x36253)
    #1 0x7f47181eb9bf in uv_thread_create 3rdparty/libuv/src/unix/thread.c:198

Thread T2 created by T0 here:
    #0 0x7f4718f39253 in pthread_create (/usr/lib/x86_64-linux-gnu/libasan.so.2+0x36253)
    #1 0x7f47181eb9bf in uv_thread_create 3rdparty/libuv/src/unix/thread.c:198

SUMMARY: AddressSanitizer: heap-use-after-free src/core/interp.c:210 MVM_interp_run
Shadow bytes around the buggy address:
  0x0c3080007c90: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c3080007ca0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c3080007cb0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c3080007cc0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c3080007cd0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
=>0x0c3080007ce0: fd fd fd fd fd[fd]fd fd fd fd fd fd fd fd fd fd
  0x0c3080007cf0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c3080007d00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c3080007d10: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c3080007d20: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c3080007d30: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07 
  Heap left redzone:       fa
  Heap right redzone:      fb
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack partial redzone:   f4
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
==5509==ABORTING