Re: [PATCH] configure: Check bzip2 is available

From: Thomas Huth <thuth@redhat.com>
To: "Peter Maydell" <peter.maydell@linaro.org>,
	"Philippe Mathieu-Daudé" <philmd@redhat.com>
Cc: "Daniel P . Berrange" <berrange@redhat.com>,
	QEMU Trivial <qemu-trivial@nongnu.org>,
	QEMU Developers <qemu-devel@nongnu.org>,
	Wainer dos Santos Moschetta <wainersm@redhat.com>,
	Gerd Hoffmann <kraxel@redhat.com>,
	Laszlo Ersek <lersek@redhat.com>
Subject: Re: [PATCH] configure: Check bzip2 is available
Date: Mon, 11 Nov 2019 12:51:05 +0100	[thread overview]
Message-ID: <ac065856-56e2-bceb-851c-a9c150068e71@redhat.com> (raw)
In-Reply-To: <CAFEAcA8EijZRqhFerQbq5cCbaq-qzrMzOrQjc6Ro=v2p6=W_pA@mail.gmail.com>

On 08/11/2019 18.10, Peter Maydell wrote:
> On Fri, 8 Nov 2019 at 17:07, Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
>> On 11/8/19 4:43 PM, Eric Blake wrote:
>>> bzip2 is no longer a favored compression.  If we are trying to pick a
>>> compression that is most likely to be present on any system, go with
>>> gzip.  If we are trying to pick a compression that packs tighter and
>>> uncompresses faster, pick xz or zstd.  But bzip2 does neither: it packs
>>> slightly tighter than gzip but has slower performance in doing so, and
>>> thus is no longer used as a default compression.
>>
>> The problem was with OpenBSD 6.1 which hadn't xz available.
>>
>> In commit 12745eaa02 Gerd updated the VM to OpenBSD 6.5 and we now have
>> access to xz. IIRC OSX supported versions also provide xz.
>>
>> If we want to revert Laszlo's patches and apply his first version (using
>> xz), we should do that during 5.0 dev cycle, now it is too late.
>> I'd prefer we simply fix bzip2 for the next release.
> 
> I don't think we should try to use 'xz' because I don't see
> the point. We should use something that's generally available,
> whether that's bzip2 or gzip. Life's too short to deal with
> yet another file compression tool and format.

FWIW, on the weekend, I accidentially came accross this page:

 https://www.nongnu.org/lzip/xz_inadequate.html

After reading that, I also don't think anymore that we should switch to
'xz'.

 Thomas