While importing libxml2-2.11.4.tar.xz through gbp:

$ gbp import-orig --pristine-tar ../libxml2-2.11.4.tar.xz
What is the upstream version? [2.11.4]
gbp:info: Importing '../libxml2-2.11.4.tar.xz' to branch 'upstream'...
gbp:info: Source package is libxml2
gbp:info: Upstream version is 2.11.4
gbp:error: Import of ../libxml2_2.11.4.orig.tar.xz failed: Couldn't
commit to 'pristine-tar' with upstream '96ab8ed14cb3
6463c3531d5f6f3c8c897d187d57': pristine-xz failed to reproduce build
of ../libxml2_2.11.4.orig.tar.xz
(Please file a bug report.)
pristine-tar: failed to generate delta
gbp:error: Error detected, Will roll back changes.
gbp:info: Rolling back branch upstream by resetting it to
7188a3bc963343a2dfc60c7510807e6c3c14aeda
gbp:info: Rolling back branch pristine-tar by resetting it to
96b561e8b4f167e53a88f8b68703c79d1735d6c2
gbp:error: Rolled back changes after import error.

The tarball is at
https://download.gnome.org/sources/libxml2/2.11/libxml2-2.11.4.tar.xz
And the git repository to import to:
https://salsa.debian.org/xml-sgml-team/libxml2/

Thanks,
Aron

Hi!

Is anyone having success using pristine-tar with upstream tarballs that use xz?

I see multiple reports that look very similar:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=918663
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=851291
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1041465
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1110375

I also noticed there was this issue in xz itself:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1063252

Wild guess: could it be related that xz supports multiple compression
levels and they are not part fo the metadata currently?

- Otto

I'm not sure it was really necessary to cross-post this across
several bugs while also CC'ing random developers (I don't think I've
ever interacted with any of the bugs you mention above).

To answer your question, libvirt and libvirt-dbus are both using
pristine-tar to import xz-compressed upstream tarballs and I'm not
aware of that ever causing any issues.