To build a package this way, the tar archive must have enough of an expected structure, such as a configure script and a Makefile with the expected make targets. The most crucial element is that the tar archive must have the package spec file.That’s because the rpmbuild command doesn’t know how to build every program in the universe. Instead, rpmbuild expects to find a spec file to tell it what to do. If you see an error like the following, then your tar archive likely is missing the spec file:

$ rpmbuild -tc vixie-cron*tar.gz

error: Name field must be present in package: (main package)

error: Version field must be present in package: (main package)

error: Release field must be present in package: (main package)

error: Summary field must be present in package: (main package)

error: Group field must be present in package: (main package)

error: License field must be present in package: (main package)

These errors show expected tags from the missing spec file.