bubbewrap cannot create namespace - Failed RTM_NEWADDR: Operation not permitted

[Satvik Patwardhan]

Hi, I am the developer of Web Apps (https://flathub.org/apps/net.codelogistics.webapps) which is a Flatpak application which uses XDG Desktop Portal's Dynamic Launcher portal to create desktop files. However, on Ubuntu 24.04, this fails with this output in the terminal:

`GDBus.Error:org.freedesktop.portal.Error.InvalidArgument: Dynamic launcher icon failed validation`

which is apparently due to Ubuntu deciding to use Apparmor to restrict the creation of user namespaces in bubblewrap.

Unfortunately I don't use Ubuntu or have any idea about what apparmor or bubblewrap are, but I have come to know from https://gitlab.gnome.org/GNOME/epiphany/-/issues/2357 and https://etbe.coker.com.au/2024/04/24/
ubuntu-24-04-bubblewrap/ that this issue is being caused by apparmor on Ubuntu. Please refer to these links for complete details about this issue.

I am using Ubuntu 24.04 LTS, GNOME 46 on Wayland and apparmor version 4.0.0-beta3-0ubuntu3.

[John Johansen (jjohansen)]

Can you please try with the apparmor in https://launchpad.net/~apparmor-dev/+archive/ubuntu/apparmor-sru
Basically from a terminal you need to do

  sudo add-apt-repository ppa:apparmor-dev/apparmor-sru
  sudo apt update

and then retry Web Apps

4.0.1 is in the SRU process, currently waiting to be promoted to 24.04 -proposed.

[Satvik Patwardhan (eyekay)]

Thank you, that solves the issue.