Closed issue by howtologinquickwiththirtyninecharacters on void-packages repository https://github.com/void-linux/void-packages/issues/20226 Description: ### System * xuname: *Void 5.4.26_1 x86_64 GenuineIntel uptodate rrFFFF* * package: *firejail-0.9.62_1* ### Expected behavior Upon executing `firejail firefox` Firefox starts and remains listed in the output of `firejail --top` ### Actual behavior Firefox starts, appears for a brief moment in the output of `firejail --top`, then closes without ever opening a window. See footnote for the output of the command. ### Steps to reproduce the behavior 1. Install Firejail and Firefox (*firefox-74.0_1* at the time of writing this) 2. (important) Make sure no other Firefox process is running 3. Run `firejail --top` on a terminal 4. (optional) Run `firejail watch echo 1` on a different terminal and confirm that it appears in the `firejail --top` output to make sure Firejail works as expected for other software 4. Run `firejail firefox` on a different terminal, confirm that Firefox does not start and examine the output of the command ### Footnotes Installing AppArmor to silence the Firejail warnings doesn't fix this issue. Other X software such as HexChat and Chromium can run inside Firejail with no issues. This was working some time ago but I can't remember the exact Firefox and Firejail versions. I think it may have been around the time of Firefox 70. Output of the command: ~~~ Reading profile /etc/firejail/firefox.profile Reading profile /etc/firejail/whitelist-usr-share-common.inc Reading profile /etc/firejail/firefox-common.profile Reading profile /etc/firejail/disable-common.inc Reading profile /etc/firejail/disable-devel.inc Reading profile /etc/firejail/disable-exec.inc Reading profile /etc/firejail/disable-interpreters.inc Reading profile /etc/firejail/disable-programs.inc Reading profile /etc/firejail/whitelist-common.inc Reading profile /etc/firejail/whitelist-var-common.inc Parent pid 4188, child pid 4189 Warning: An abstract unix socket for session D-BUS might still be available. Use --net or remove unix from --protocol set. Warning: /sbin directory link was not blacklisted Warning: /usr/sbin directory link was not blacklisted Post-exec seccomp protector enabled Seccomp list in: !chroot, check list: @default-keep, prelist: unknown, Warning: Cannot confine the application using AppArmor. Maybe firejail-default AppArmor profile is not loaded into the kernel. As root, run "aa-enforce firejail-default" to load it. Child process initialized in 118.78 ms Parent is shutting down, bye... ~~~