On Debian Stretch with chromium 72.0.3626.96-1~deb9u1, the browser crashes whenever being passed --remote-debugging-port or --headless. It is an Upstream issue:
chromium crashes when started with --remote-debugging-port switch
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=922794
$ /usr/bin/chromium --remote-debugging-port=9222 --user-data-dir=/tmp/remote Gtk-Message: Failed to load module "canberra-gtk-module" ATTENTION: default value of option force_s3tc_enable overridden by environment. Received signal 11 SEGV_MAPERR 000000000080 #0 0x55d7796c2711 <unknown> #1 0x55d7796c2b7b <unknown> #2 0x55d7796c31de <unknown> #3 0x7f1449f730e0 <unknown> #4 0x55d777aaa314 <unknown> #5 0x55d777ab51b7 <unknown> #6 0x55d77b237634 <unknown> #7 0x55d77917af7f <unknown> #8 0x55d7791b24cc <unknown> #9 0x55d7791b25ee <unknown> #10 0x55d7791c33d3 <unknown> #11 0x55d7791c3e55 <unknown> #12 0x55d777a46fd3 <unknown> #13 0x55d777ec0c32 <unknown> #14 0x55d777a49089 <unknown> #15 0x55d777a4a039 <unknown> #16 0x55d777a365be <unknown> #17 0x55d77916d298 <unknown> #18 0x55d77916d501 <unknown> #19 0x55d77916d8b0 <unknown> #20 0x55d779178b7a <unknown> #21 0x55d77916b6c5 <unknown> #22 0x55d776e13d39 ChromeMain #23 0x7f143c39d2e1 __libc_start_main #24 0x55d776e13b8a _start r8: 0000000000000003 r9: 0000000000000040 r10: 00007f13a5ffb9d0 r11: 0000000000000202 r12: 00007fff965b8790 r13: 000055d781056680 r14: 00007fff965b87e0 r15: 000055d781055f60 di: 00007fff965b8790 si: 000055d77e25a770 bp: 00007fff965b8830 bx: 000055d781056060 dx: 000055d777aaa314 ax: 00007fff965b8790 cx: 0000000000000319 sp: 00007fff965b8730 ip: 000055d777aaa314 efl: 0000000000010202 cgf: 002b000000000033 erf: 0000000000000004 trp: 000000000000000e msk: 0000000000000000 cr2: 0000000000000080 [end of stack trace] Calling _exit(1). Core file will not be generated.
Chromium 70.0.3538.110-1~deb9u1 is not affected.