Is it known problem, that zfs.ko could not be built with system compiler (clang 3.9.1) without optimization?

[Slawa Olhovchenkov]

On Wed, Feb 22, 2017 at 11:47:42PM +0300, Lev Serebryakov wrote:

> Hello Freebsd-stable,
> 
>    Now if you build zfs.ko with -O0 it panics on boot.
> 
>    If you use default optimization level, a lot of fbt DTreace probes are
>   missing.

Is this related to http://llvm.org/bugs/show_bug.cgi?id=18420 ?