Re: [gentoo-dev] Guidance on adding kernel config checks to ebuilds

[Mike Gilbert]

On Mon, Sep 27, 2021 at 12:23 PM Mike Pagano <mpagano@g.o> wrote:
>
> On 9/27/21 12:10 PM, Mike Gilbert wrote:
> > I'm looking to solicit opinions on when it is appropriate for an
> > ebuild to check for kernel config options using linux-info.eclass. I
> > don't think we have any guidelines documented, instead leaving it up
> > to the "common sense" of package maintainers.
> >
> > Adding linux-info calls to pkg_pretend or pkg_setup causes slowdowns
> > when running emerge, so we should do so only when there is a
> > compensating benefit. It doesn't make sense to check for kernel
> > options that are very commonly enabled. But what is "very common"?
> >
> > An obvious example would be CONFIG_INET, which controls IPv4 support
> > in the kernel. It does not make sense to check for that in every
> > package that uses AF_INET sockets.
> >
> > A less obvious example: a user filed a bug against net-misc/dhcpcd
> > today asking that we check for CONFIG_PACKET [1]. My first thought was
> > "why would you ever disable that?". The option description even says
> > "if unsure, say Y". However, I suppose it is technically possible to
> > run a Linux system with it disabled.
> >
> > I think a reasonable rule of thumb would be to assume we can rely on
> > options that are enabled by "make defconfig". If the user chooses to
> > disable them, they are responsible for anything that breaks.
> >
> > Thoughts?
> >
> > [1] https://bugs.gentoo.org/815064
> >
>
> The challenge I see is that these config checks head off bugs and issues without our intervention.
>
> We as kernel maintainers depend on ebuild maintainers to check these things so they don't become "kernel bugs" to figure out.

I guess I'm proposing that we set some minimal standard for kernel
configs. It's a waste of time and effort to pepper random ebuilds with
checks for options that everyone should have enabled in the first
place.