Subject: [bug#33643] [PATCH] gnu-build-system: Enable xz to decompress in parallel.

From: Leo Famulari <[email-masked]>
Date: Thu, 6 Dec 2018 16:06:53 -0500

On Thu, Dec 06, 2018 at 07:38:21PM +0000, Christopher Baines wrote:
> So, if -T was used to compress the data, then it sounds like it'll work
> to decompress it. I guess this adds a little more uncertainty to the
> benefit of this change, as the impact is dependent on the way the source
> data is compressed.

Right. When parallel decompression is implemented, I think we should
enable it in order to get some benefit from upstream tarballs that may
have been created with multi-threaded compression. 

However, we probably won't be able to use the parallel compression
within Guix because it is apparently not deterministic:

<https://bugs.gnu.org/31015>