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Date: Mon, 09 Feb 2015 17:47:10 -0500
From: Nikolai Lifanov <lifanov@mail.lifanov.com>
To: Glen Barber <gjb@freebsd.org>
Subject: Re: svn commit: r278450 - head/release
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On 2015-02-09 05:46, Glen Barber wrote:
> Author: gjb
> Date: Mon Feb  9 10:46:39 2015
> New Revision: 278450
> URL: https://svnweb.freebsd.org/changeset/base/278450
> 
> Log:
>   Revert r278445.
> 
>   I was going to use __FreeBSD_version to determine if
>   xz(1) should be multi-threaded by default, but doing
>   this will cause problems if/when the changes are merged
>   from head.
> 
>   Sponsored by:	The FreeBSD Foundation
> 
> Modified:
>   head/release/Makefile
> 
> Modified: head/release/Makefile
> 

Can you just X-MFC this with xz 5.2.0 import?
You can then refer to xz in OBJDIR to get this to work on older 
releases.

- Nikolai Lifanov