[PATCH] Linux: Remove <sys/sysctl.h> and the sysctl function

[Florian Weimer]

* Vineet Gupta via Libc-alpha:

> On 3/11/20 1:19 PM, Zack Weinberg wrote:
>> So I withdraw my objections to your original patch.  We can always put
>> sys/sysctl.h back in the future if someone does the work to write the
>> emulation.
>
> My 2 cents. Can we _not_ remove the header per-se. This can certainly cause
> arbitrary packages to build time fail (vs. runtime failure from sysctl returning
> -1 or some such). Propagation of such fixes in build systems it may take a while.
> Consider my personal woe with stime removal in context of Buildroot/busybox.
> Despite them fixed in busybox not all moving parts are aligned still and we have
> to carry such patches locally to be able to even build glibc 2.31+ there.

Why aren't those patches upstream yet?  (I'm not blaming you, I'm just
trying to understand what is going on.)

Are you in a special position becaue you have to use a newer glibc for
your port, and everybody else using this distribution is sticking with
an older glibc?

glibc's approach to removals is inconsistent at best.  stime was never
deprecated and removed directly, for example.  There is also the issue
that configure scripts ignore deprecation warnings, which then can
lead to build issues later one, something that does not happen with
removed interfaces (which are obviously not detected by configure
scripts).

And specific to sysctl, the removal of the header and function
actually fixes bugs in a few packages.