firejail tree+list flags bypass hidepid mounted /proc displaying details of other users sandboxes

[ghost]

Is this a bug or the intended behavior? It seems like it would be a bug since using firemon with/without the --tree/--list flags fails as expected with the message:
Error: /proc is mounted hidepid, you would need to be root to run this command

If it is intentional is there a setting that will "fix" it?

firejail version information(Fedora 34):

firejail version 0.9.64.4

Compile time support:
	- AppArmor support is disabled
	- AppImage support is enabled
	- chroot support is enabled
	- D-BUS proxy support is enabled
	- file and directory whitelisting support is enabled
	- file transfer support is enabled
	- firetunnel support is enabled
	- networking support is enabled
	- overlayfs support is disabled
	- private-home support is enabled
	- private-cache and tmpfs as user enabled
	- SELinux support is enabled
	- user namespace support is enabled
	- X11 sandboxing support is enabled

[rusty-snake]

I converted this to #4705 as it looks like a CWE-200 bug.

[reinerh]

Is this bug also in 0.9.66?
When I run firejail --tree (or --list) inside a firejail sandbox I only get the error:

Warning: an existing sandbox was detected. /bin/bash will run without any additional sandboxing features

[ghost]

I don't believe firejail supports being run within a firejail sandbox in ?any? way. I get the same error by just trying to run firejail with the --help flag if it's already in a sandbox.