Trying to load the executable and the core produced by it on a 64-bit Linux machine into gdb running on 32-bit FreeBSD box, I reliably get a core dump from the debugger itself:

% gdb801 mx core.39591
GNU gdb (GDB) 8.0.1 [GDB v8.0.1 for FreeBSD]
Copyright (C) 2017 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "i386-portbld-freebsd11.1".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Помилка адресації(записано core)
% gdb801 gdb801 gdb801.core
...
Reading symbols from gdb801...(no debugging symbols found)...done.
[New LWP 100203]
Core was generated by `gdb801 mx core.39591'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x088ef100 in htab_remove_elt ()
(gdb) where
#0  0x088ef100 in htab_remove_elt ()
#1  0x08432c79 in tdesc_use_registers(gdbarch*, target_desc const*, tdesc_arch_data*) ()
#2  0x0813d8f9 in ?? ()
#3  0x0838764f in gdbarch_find_by_info(gdbarch_info) ()
#4  0x082e350e in set_gdbarch_from_file(bfd*) ()
#5  0x0836d4e3 in exec_file_attach(char const*, int) ()
#6  0x083bdf53 in ?? ()
#7  0x083bda29 in gdb_main(captured_main_args*) ()
#8  0x080f56a9 in main ()