Description of problem:
I had been having trouble using rpmbuild to build RPMs from tarballs.
I tracked this down eventually to a change in behaviour in the new version of
tar.  Without setting TAR_OPTIONS to "--wildcards", the tarball is not extracted.

This change in behaviour should at least be documented.

Version-Release number of selected component (if applicable):
tar-1.15.91-1.FC5

How reproducible:
Every time

Steps to Reproduce:
1. rpmbuild -ta <tarball with .spec file inside)
2.
3.
  
Actual results:
rpmbuild fails because the tarball is not extracted

Expected results:
rpmbuild proceeds normally

Additional info:
The behaviour change is documented here:
http://www.gnu.org/software/tar/manual/html_node/Changes.html