The librpmbuild library uses the macro definition of MKDIR_P from config.h. It should use the definition of %__mkdir_p in the macros file so that its value can be changed without having to rebuild.
Changing component.
Closing bugs on older, no longer supported, releases. Apologies for any lack of response. For RPM issues, please try a current release such as Fedora Core 4; if bugs persist, please open a new issue.