Here is how you can build an rpm from a src.rpm on Fedora!
1. First install some needed packages:
$ sudo yum install @development-tools $ sudo yum install fedora-packager
2. Next, as regular user (_not_ root) type this command with your src.rpm:
$ rpm -ivh package.src.rpm
3. Next, go to the following directory:
$ cd rpmbuild/SPECS/
4. Now build the rpm package.
$ rpmbuild -ba thepackage.spec
5. rpms are then available in rpmbuild/RPMS/x86_64/ (for 64bit, as an example).
$ cd rpmbuild/RPMS/x86_64/
Install with tack i:
$ sudo rpm -i thepackage.rpm