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

[Luca Barbato]

On 27/09/21 18:10, 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?

We can document in the wiki that going against defconfig means you keep
the pieces when something explodes colorfully and/or come up with a even
smaller list of config items expected.


lu