[bitbang]

If I understand it correctly, landlock is an API used by an app to sandbox itself. The app itself controls the sandboxing. Bubble wrap is user space tooling external to the app, so the app had no direct awareness or control of its sandboxing. The scenarios each is intended for are orthogonal to one another.

[amarshall]

Landlock can be used to sandbox a launched sub process, as it is here, just as the Kernel APIs used by Bubblewrap could (and sometimes are!) used by programs to sandbox themselves.

[1oooqooq]

not exactly correct. bubblewrap, firejail, and i not sure, but maybe even apparmour, all remove capabilities and create+join restricted fs/net namespaces, and then fork the actual thing you want to execute. so it's exactly the same concept, but those use the cap and cgroups.