Bug#1028970: complains to stderr about "unknown extended header keyword"

[Marco d'Itri]

Package: tar
Version: 1.34+dfsg-1.1
Severity: important

Emitting these warnings to stderr is bad because it breaks other
software which calls tar and does not expect something on stderr.
Either the warnings are useless, and then they should just be
suppressed, or they are relevant, and then tar should be taught about
whatever a "LIBARCHIVE.xattr.com.apple.lastuseddate" is.

To reproduce:

$ wget https://cpan.metacpan.org/authors/id/M/MR/MRSCOTTY/Crypt-X509-0.55.tar.gz
$ LANG=C tar tvvf Crypt-X509-0.55.tar.gz > /dev/null
tar: Ignoring unknown extended header keyword 'LIBARCHIVE.xattr.com.apple.lastuseddate#PS'
tar: Ignoring unknown extended header keyword 'LIBARCHIVE.xattr.com.apple.lastuseddate#PS'
$

--
ciao,
Marco

[Marco d'Itri]

Control: severity -1 critical

> Emitting these warnings to stderr is bad because it breaks other
> software which calls tar and does not expect something on stderr.

And indeed, now lintian starts emitting errors:

E: libcrypt-x509-perl source: unpack-message-for-orig libcrypt-x509-perl_0.55.orig.tar.gz . tar: Ignoring unknown extended header keyword 'LIBARCHIVE.xattr.com.apple.lastuseddate#PS'

--
ciao,
Marco

[Janos LENART]

severity 1028970 wishlist

tag 1028970 wontfix

thanks

Marco, tar doesn't document a standard for stderr. In particular, this looks like a legit warning in either case. Please bring this up with the software that is broken by it.