https://bugzilla.redhat.com/show_bug.cgi?id=1723013
--- Comment #12 from Artur Frenszek-Iwicki fedora@svgames.pl --- I don't think we have a requirement as to which release one has is allowed to use for building SRPMs for review, though I guess the unspoken expectation is "something that's not EOL". That being said, you can use mock, or koji scratch builds to verify that your package builds fine on Fedora Rawhide. https://fedoraproject.org/wiki/Using_the_Koji_build_system#Scratch_Builds https://fedoraproject.org/wiki/Using_Mock_to_test_package_builds
Once you have a successful scratch build, it's good to add a link to it alongside the SPEC and SRPM - just for showing reviewers that the package builds fine.