The rpmbuild command is used to build RPM (Red Hat Package Manager) packages. If you receive the error "error: Installed (but unpackaged) file(s) found," it means that rpmbuild has detected files in the package that are not listed in the %files section of the RPM spec file.
To fix this error, you will need to add the missing files to the %files section of the RPM spec file. The %files section specifies the list of files that should be included in the RPM package.
For example, if the error message lists a file /usr/local/bin/foo, you can add the following line to the %files section of the RPM spec file:
%files ... /usr/local/bin/foo ...
Make sure to include all the files listed in the error message in the %files section.
After making the necessary changes to the RPM spec file, you can try building the package again using the rpmbuild command.
It's always a good idea to carefully review the documentation and ensure that all the necessary files are included in the %files section of the RPM spec file. This will help ensure that the RPM package builds correctly and contains all the necessary files.