[Aboriginal] musl and kernel headers [was Re: system-images 1.4.2: od is broken; bzip2 is missing]

[Denys Vlasenko]

On Tue, Oct 6, 2015 at 4:30 PM, Rich Felker <dalias at aerifal.cx> wrote:
> On Mon, Oct 05, 2015 at 09:24:01PM -0500, Rob Landley wrote:
>> On 10/05/2015 08:44 PM, Rich Felker wrote:
>> > The cleaner approach is just avoiding including both the kernel
>> > headers and libc/userspace headers for the same things in the same
>> > file. In theory this may be hard in some cases, but I find that I can
>> > almost always fix these sorts of errors during a build by commenting
>> > out one or two #include lines.
>>
>> I am _deeply_ curious how you'd get linux/loop.h on a platform where you
>> need the 32 bit loopback structure definition without including the
>> kernel header.
>
> Sorry I wasn't clear on this; the meaning I intended to convey was
> including both kernel and libc/userspace headers for the same things.
> Network is the main area affected here. The kernel headers have fixed
> up all the gratuitous conflicts with userspace, but the big remaining
> ones are places where they want to define types with the exact same
> names, which mostly happens in network. So what I was trying to say is
> that programs using kernel network headers (legitimately for
> linux-specific stuff) are going to best avoid the risk of clashes by
> not including libc network headers in the same files.

For me as a libc user, the gist of the story is:
I switch to musl, things break.

Apart from linux/* includes, utmp/wtmp also broke.