Bug#829100: lintian: [patch] Warn about over-eagerly xz-compressed data.tar.xz

[Guillem Jover <guillem@debian.org>]

Hi!

On Thu, 2016-06-30 at 17:23:46 +0200, Christoph Biedl wrote:
> Package: lintian
> Version: 2.5.45
> Severity: wishlist
> Tags: patch

> as not known to everybody, xz's higher compression levels have -
> besides improving compression of big files - the side effect of taking
> a lot of memory for the dictionary, even when unpacking. There is
> however no sense in using a compression level that (roughly) takes
> more DictSize than the size of the uncompressed file. [1] has a
> discussion on this,

Thanks for filing this, I had it on my TODO after I posted it on
debian-devel in 2014! Something else I don't have to do. :)

  <https://lists.debian.org/debian-devel/2014/09/msg00013.html>

> | $ ar x traceroute_1%3a2.0.20-2+b1_armel.deb data.tar.xz
> | $ xz --list --verbose --verbose data.tar.xz
> | (...)
> |   Compressed size:    47,9 KiB (49.056 B)
> |   Uncompressed size:  130,0 KiB (133.120 B)
> | (...)
> |   Memory needed:      65 MiB
> | (...)

As mentioned on that thread, you might want to use --robot which is
the supported interface for other tools to use.

Thanks,
Guillem