Barebone kernel options request

[Kamila Součková]

> there's things in kernel-land that i'd like to avoid but i've seen no
options so far for it. (like as it could be nooptions JAIL)
> I'm already aware of kernel configuration file, i'm just asking if one
can help to get like that (some kind of patch that would add code like
#ifdef JAIL ... #endif).

I believe removing jails cannot be done with just the config file and would
be a lot of work to do at all. That said, I wouldn't remove them even if I
could and didn't need them for isolating services: jails can also be useful
for a variety of "unexpected" purposes, such as building ports with
poudriere, poking at boot environments, or even playing with linuxulator.
On several of my systems, I have zero jails running by default, yet I
consider it useful to have them available when the need arises :-)

Kamila