Bug#900593: diffoscope: GNU tar xattrs result in: libarchive: Ignoring malformed pax extended attribute

[Tianon Gravi]

On Fri, 1 Jun 2018 at 14:16, Chris Lamb <lamby at debian.org> wrote:
> Oh, neat! Hm, can you try:
>
>   --pax-option=exthdr.name=%d/PaxHeaders/%f,atime:=0

Hey, that's snazzy!  That gives me a reproducible result. :)

Without:

$ sudo tar --create --directory wtf --numeric-owner --transform
's,^./,,' --sort name --xattrs . | md5sum
7ce7cc6c2ad85b1f6fbe2e061188c7a0  -
$ sudo tar --create --directory wtf --numeric-owner --transform
's,^./,,' --sort name --xattrs . | md5sum
48d6da7b220e95ce913b0ab69e7edcd3  -

With:

$ sudo tar --create --directory wtf --numeric-owner --transform
's,^./,,' --sort name --xattrs
--pax-option=exthdr.name=%d/PaxHeaders/%f,atime:=0 . | md5sum
b45e8c1739b34f844731e94afc2ccaac  -
$ sudo tar --create --directory wtf --numeric-owner --transform
's,^./,,' --sort name --xattrs
--pax-option=exthdr.name=%d/PaxHeaders/%f,atime:=0 . | md5sum
b45e8c1739b34f844731e94afc2ccaac  -

And after running "sudo setcap cap_net_raw+ep wtf/bin/ping" (to make
sure there are some caps that actually need to be represented):

$ sudo tar --create --directory wtf --numeric-owner --transform
's,^./,,' --sort name --xattrs
--pax-option=exthdr.name=%d/PaxHeaders/%f,atime:=0 . | md5sum
ce0aa6ac1b6fc9df117696cc17cb07b3  -
$ sudo tar --create --directory wtf --numeric-owner --transform
's,^./,,' --sort name --xattrs
--pax-option=exthdr.name=%d/PaxHeaders/%f,atime:=0 . | md5sum
ce0aa6ac1b6fc9df117696cc17cb07b3  -


♥,
- Tianon
  4096R / B42F 6819 007F 00F8 8E36  4FD4 036A 9C25 BF35 7DD4