Panic when running t/spec/S12-meta/primitives.t

gistfile1.txt

Thread 1 "moar" hit Breakpoint 1, MVM_panic (exitCode=1, messageFormat=0x7ffff76b1258 "Collectable %p in fromspace accessed") at src/core/exceptions.c:830
830	MVM_NO_RETURN void MVM_panic(MVMint32 exitCode, const char *messageFormat, ...) {
(gdb) bt
#0  MVM_panic (exitCode=1, messageFormat=0x7ffff76b1258 "Collectable %p in fromspace accessed") at src/core/exceptions.c:830
#1  0x00007ffff75c0661 in append_guard (tc=0x555555758cc0, base_guards=0x0, resolved=0x555557a162b8, barrier=0x555558c1c5b0) at src/spesh/plugin.c:168
#2  0x00007ffff75c137a in add_resolution_to_guard_set (tc=0x555555758cc0, sr_data=0x555558d02b80) at src/spesh/plugin.c:306
#3  0x00007ffff74b3c50 in remove_one_frame (tc=0x555555758cc0, unwind=0 '\000') at src/core/frame.c:948
#4  0x00007ffff74b3fd3 in MVM_frame_try_return (tc=0x555555758cc0) at src/core/frame.c:1024
#5  0x00007ffff747836d in MVM_interp_run (tc=0x555555758cc0, initial_invoke=0x7ffff762e425 <toplevel_initial_invoke>, invoke_data=0x5555557fe178) at src/core/interp.c:543
#6  0x00007ffff762e58a in MVM_vm_run_file (instance=0x555555758260, filename=0x7fffffffe320 "/home/dogbert/repos/rakudo/perl6.moarvm") at src/moar.c:444
#7  0x000055555555581a in main (argc=10, argv=0x7fffffffde98) at src/main.c:302
(gdb) f 1
#1  0x00007ffff75c0661 in append_guard (tc=0x555555758cc0, base_guards=0x0, resolved=0x555557a162b8, barrier=0x555558c1c5b0) at src/spesh/plugin.c:168
168	                    MVM_ASSIGN_REF(tc, &(barrier->common.header),
(gdb) l
163	                    MVM_ASSIGN_REF(tc, &(barrier->common.header),
164	                            result->guards[insert_pos].u.object,
165	                            tc->plugin_guards[i].u.object);
166	                    break;
167	                case MVM_SPESH_PLUGIN_GUARD_TYPE:
168	                    MVM_ASSIGN_REF(tc, &(barrier->common.header),
169	                            result->guards[insert_pos].u.type,
170	                            tc->plugin_guards[i].u.type);
171	                    break;
172	                case MVM_SPESH_PLUGIN_GUARD_CONC:
(gdb) p tc->plugin_guards[i].u.type
$1 = (MVMSTable *) 0x55555575c8f8
(gdb) c
Continuing.
MoarVM panic: Collectable 0x55555575c8f8 in fromspace accessed

here's the BT from the last GC before the error occurs

1..20
Obtained 12 stack frames.
//home/dogbert/repos/rakudo/nqp/MoarVM/../../install/lib/libmoar.so(print_trace+0x30) [0x7fabc49f5365]
//home/dogbert/repos/rakudo/nqp/MoarVM/../../install/lib/libmoar.so(MVM_gc_enter_from_allocator+0x462) [0x7fabc49f5869]
//home/dogbert/repos/rakudo/nqp/MoarVM/../../install/lib/libmoar.so(MVM_gc_allocate_nursery+0x70) [0x7fabc49f60b4]
//home/dogbert/repos/rakudo/nqp/MoarVM/../../install/lib/libmoar.so(MVM_gc_allocate) [0x7fabc49f5eaf]
//home/dogbert/repos/rakudo/nqp/MoarVM/../../install/lib/libmoar.so(MVM_gc_allocate_zeroed+0x23) [0x7fabc49f613d]
//home/dogbert/repos/rakudo/nqp/MoarVM/../../install/lib/libmoar.so(MVM_gc_allocate_object+0x3b) [0x7fabc49f64e0]
//home/dogbert/repos/rakudo/nqp/MoarVM/../../install/lib/libmoar.so(MVM_repr_alloc_init+0x43) [0x7fabc4a2194d]
//home/dogbert/repos/rakudo/nqp/MoarVM/../../install/lib/libmoar.so(setup_for_guard_recording)) [0x7fabc4acb74b]
//home/dogbert/repos/rakudo/nqp/MoarVM/../../install/lib/libmoar.so(call_resolver) [0x7fabc4acb930]
//home/dogbert/repos/rakudo/nqp/MoarVM/../../install/lib/libmoar.so(MVM_spesh_plugin_resolve+0x11b) [0x7fabc4acbb71]
//home/dogbert/repos/rakudo/nqp/MoarVM/../../install/lib/libmoar.so(MVM_interp_run+0x2b282) [0x7fabc49aa49b]
//home/dogbert/repos/rakudo/nqp/MoarVM/../../install/lib/libmoar.so(MVM_vm_run_file+0x113) [0x7fabc4b388e7]
MoarVM panic: Collectable 0x1c02578 in fromspace accessed