All you have to know about RPM

To see the Macro configuration used by RPM, issue the command:

rpm --showrc

Here's an example output showing that the macro named "_repackage_dir" has the value "/var/spool/repackage":

# rpm --showrc | grep repackage
-14: _repackage_all_erasures    0
-14: _repackage_dir     /var/spool/repackage
-14: _repackage_name_fmt        %%{NAME}-%%{VERSION}-%%{RELEASE}.%%{ARCH}.rpm
-14: _repackage_root    %{nil}