Comment # 9 on bug 1127188 from Richard Biener

(In reply to Michal Suchanek from comment #7)
> I don't know what you call those
> 
> aarch64-suse-linux-gcc
> 
> and similar.

Those are a convenience provided to you kernel folks who requested
they'd be available without the hassle to untar an icecream environment.

> They are crosscompilers without a libc.
> 
> We need libc headers to build mainline kernel.

Seems to be a new thing.  In theory extending the "hack" to libc (headers)
is possible by re-packaging the native glibc into a noarch cross-%arch-glibc
package and build depending on that.  But this seemed to gross for me.

I also don't really have time to explore this route again (did once during
a hackweek).