In RHEL5.9, rpm-build macros dereferences the xz binary.

Issue

• The file /usr/lib/rpm/macros uses %{_bindir} to dereference the xz binary for decompressing tar files compressed with xz.
• When building an RPM whose prefix is not /usr (such as /usr/local) rpmbuild will try to use /usr/local/bin/xz instead of /usr/bin/xz to decompress the source .tar.xz file and fail.
• Other compression binary references in /usr/lib/rpm/macros (unzip, bzip2, gzip, etc.) use absolute pathnames and are not dereferenced.