DDD 3.3.12 (x86_64-unknown-cygwin) gets `Segmentation fault' signal

Hi DDD,

Today I’ve been trying to debug lwIP, and in tcp.c in line 579 there is an array tcp_pcb_lists that contains pointers to heads of lists of sockets (4 of them). The lists are empty so the pointers are NULL  at this point of SW execution. I displayed the array, and then went on to display the pointers to heads. So far all was fine. Then I stepped (“nexted” sounds somewhat funny), and then the DDD crashed. 
I’m working in Cygwin, using 
GNU DDD 3.3.12 (x86_64-unknown-cygwin),
GNU gdb (GDB) 8.0 for arm-eabi-elf

BR,
M.W.