ajh92@ajh92-pc:~$ firejail --debug --allow-debuggers gdb firefox
Autoselecting /bin/bash as shell
Command name #gdb#
Attempting to find default.profile...
Found default profile in /usr/local/etc/firejail directory
Reading profile /usr/local/etc/firejail/default.profile
Reading profile /usr/local/etc/firejail/disable-common.inc
Reading profile /usr/local/etc/firejail/disable-programs.inc
Reading profile /usr/local/etc/firejail/disable-passwdmgr.inc

** Note: you can use --noprofile to disable default.profile **

DISPLAY :0.0, 0
Using the local network stack
Parent pid 5671, child pid 5672
Initializing child process
Host network configured
PID namespace installed
Mounting tmpfs on /run/firejail/mnt directory
Creating empty /run/firejail/mnt/seccomp.i386 file
Creating empty /run/firejail/mnt/seccomp.amd64 file
Creating empty /run/firejail/mnt/seccomp file
Creating empty /run/firejail/mnt/seccomp.protocol file
Build protocol filter: unix,inet,inet6
sbox run: /usr/local/lib/firejail/fseccomp protocol build unix,inet,inet6 /run/firejail/mnt/seccomp.protocol (null)
Dropping all capabilities
Username ajh92, no supplementary groups
Mounting read-only /bin, /sbin, /lib, /lib32, /lib64, /usr, /etc, /var
Mounting tmpfs on /var/lock
Mounting tmpfs on /var/tmp
Mounting tmpfs on /var/log
Mounting tmpfs on /var/lib/dhcp
Mounting tmpfs on /var/lib/snmp
Mounting tmpfs on /var/lib/sudo
Create the new utmp file
Mount the new utmp file
Cleaning /home directory
Sanitizing /etc/passwd, UID_MIN 1000
Sanitizing /etc/group, GID_MIN 1000
Disable /run/firejail/network
Disable /run/firejail/bandwidth
Disable /run/firejail/name
Disable /run/firejail/x11
Remounting /proc and /proc/sys filesystems
Remounting /sys directory
Disable /sys/firmware
Disable /sys/hypervisor
Disable /sys/module
Disable /sys/power
Disable /sys/kernel/debug
Disable /sys/kernel/vmcoreinfo
Disable /sys/kernel/uevent_helper
Disable /proc/sys/fs/binfmt_misc
Disable /proc/sys/kernel/core_pattern
Disable /proc/sys/kernel/modprobe
Disable /proc/sysrq-trigger
Disable /proc/sys/kernel/hotplug
Disable /proc/sys/vm/panic_on_oom
Disable /proc/irq
Disable /proc/bus
Disable /proc/sched_debug
Disable /proc/timer_list
Disable /proc/timer_stats
Disable /proc/kcore
Disable /proc/kallsyms
Disable /dev/port
Disable /dev/kmsg
Disable /proc/kmsg
Error: cannot establish communication with the parent, exiting...