Drawing the Line
Fakeroot-ng's design makes it possible to emulate just about any behavior that root can do, without escalating privileges. In fact, the "user mode linux" project emulates an entire kernel using the very same ptrace technology employed by fakeroot-ng. Just because it is possible to run an entire kernel this way, however, does not mean this is desired.
Out of Scope
Some capabilities available for a root user are simply out of scope for the fakeroot-ng project. The following layers of emulation are, theoretically, possible in fakeroot-ng, but no such support is planned.
- Mount namespaces
- Privileges drop
- Proc filesystem emulation (under consideration)