<div dir="ltr"><div>When using {message, {process_dump}} in a trace the VM can abort on OTP R16B03 to 18.0.2 (not R16B02 and earlier) on a linux 3.19.0-21-generic x86_64:<br><br>TYPE ASSERTION FAILED, file beam/erl_term.c, line 115: tag_val_def: 0x7f9c183ee6d2<br>Aborted (core dumped)<br><br></div><div>#0  0x00007f9c1c56f267 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:55<br>#1  0x00007f9c1c570eca in __GI_abort () at abort.c:89<br>#2  0x000000000056dfd1 in et_abort (expr=0x9081e0 <msg> "tag_val_def: 0x7f9c183ee6d2", file=0x64fe45 "beam/erl_term.c", line=115) at beam/erl_term.c:48<br>#3  tag_val_def (x=x@entry=140308398401234) at beam/erl_term.c:115<br>#4  0x00000000004cf12e in print_term (obj_base=<optimised out>, dcount=<synthetic pointer>, obj=140308398401234, arg=0x7f9c1d780078, fn=0x630a10 <write_ds>) at beam/erl_printf_term.c:352<br>#5  erts_printf_term (fn=0x630a10 <write_ds>, arg=0x7f9c1d780078, term=<optimised out>, precision=99999, term_base=<optimised out>) at beam/erl_printf_term.c:657<br>#6  0x000000000062ed17 in erts_printf_format (fn=fn@entry=0x630a10 <write_ds>, arg=arg@entry=0x7f9c1d780078, fmt=fmt@entry=0x64830b "%T\n", ap=ap@entry=0x7f9c198fc640) at common/erl_printf_format.c:847<br>#7  0x0000000000631750 in erts_vdsprintf (dsbufp=dsbufp@entry=0x7f9c1d780078, format=format@entry=0x64830b "%T\n", arglist=arglist@entry=0x7f9c198fc640) at common/erl_printf.c:459<br>#8  0x00000000004a9696 in erts_print (to=to@entry=-4, arg=arg@entry=0x7f9c1d780078, format=format@entry=0x64830b "%T\n") at beam/utils.c:400<br>#9  0x00000000004ea8cf in stack_element_dump (yreg=2, sp=0x7f9c183ef258, to_arg=0x7f9c1d780078, to=-4) at beam/erl_process.c:12546<br>#10 erts_stack_dump (to=to@entry=-4, to_arg=to_arg@entry=0x7f9c1d780078, p=p@entry=0x7f9c1bb003d8) at beam/erl_process.c:12466<br>#11 0x000000000055b56d in print_process_info (to=to@entry=-4, to_arg=to_arg@entry=0x7f9c1d780078, p=p@entry=0x7f9c1bb003d8) at beam/break.c:339<br>#12 0x000000000052cc20 in db_prog_match (c_p=c_p@entry=0x7f9c1bb003d8, bprog=0x7f9c1bdc0b78, term=term@entry=18446744073709551611, base=base@entry=0x0, termp=termp@entry=0x7f9c198fca70, arity=arity@entry=1, <br>    in_flags=ERTS_PAM_TMP_RESULT, return_flags=0x7f9c198fca14) at beam/erl_db_util.c:2404<br>#13 0x000000000052e5ec in erts_match_set_run (p=p@entry=0x7f9c1bb003d8, mpsp=<optimised out>, args=args@entry=0x7f9c198fca70, num_args=num_args@entry=1, in_flags=in_flags@entry=ERTS_PAM_TMP_RESULT, <br>    return_flags=return_flags@entry=0x7f9c198fca14) at beam/erl_db_util.c:1243<br>#14 0x00000000004a0c55 in erts_call_trace (p=p@entry=0x7f9c1bb003d8, mfa=mfa@entry=0x7f9c1822f058, match_spec=<optimised out>, args=0x7f9c198fca70, args@entry=0x7f9c1bfc4180, local=local@entry=1, <br>    tracer_pid=0x7f9c1bb003e8, tracer_pid@entry=0x7f9c198fdcc8) at beam/erl_trace.c:1873<br>#15 0x0000000000455654 in do_call_trace (c_p=0x7f9c1bb003d8, I=0x7f9c1822f070, reg=0x7f9c1bfc4180, local=local@entry=1, ms=<optimised out>, tracer_pid=tracer_pid@entry=75) at beam/beam_bp.c:900<br>#16 0x0000000000459524 in erts_generic_breakpoint (c_p=0x7f9c1bb003d8, I=0x7f9c1822f070, reg=0x7f9c1bfc4180) at beam/beam_bp.c:626<br>#17 0x0000000000443f23 in process_main () at beam/beam_emu.c:4921<br>#18 0x00000000004d6415 in sched_thread_func (vesdp=0x7f9c1ae4bc40) at beam/erl_process.c:8021<br>#19 0x000000000062d0e3 in thr_wrapper (vtwd=0x7fff8a43d010) at pthread/ethread.c:114<br>#20 0x00007f9c1cb136aa in start_thread (arg=0x7f9c198fe700) at pthread_create.c:333<br>#21 0x00007f9c1c640eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109<br><br>A minimal example:<br><br>c("test.erl"),<br>dbg:tracer(),<br>dbg:p(self(), [call]),<br>dbg:tpl(test, identity, [{'_',[],[{message,{process_dump}}]}]),<br></div><div>test:sum(<<0>>, 0).<br></div><div><br>test.erl:<br><br>-module(test).<br><br></div>-export([sum/2]).<br><br>sum(<<Int, Rest/binary>>, Acc) -><br>    sum(Rest, Acc + identity(Int));<br>sum(<<>>, Acc) -> Acc.<br><br>identity(Int) -><br>    Int.<br></div>