$ git clone -n https://src.fedoraproject.org/rpms/fftw2.git /var/lib/mock/f45-build-8946-397/root/chroot_tmpdir/scmroot/fftw2
Cloning into '/var/lib/mock/f45-build-8946-397/root/chroot_tmpdir/scmroot/fftw2'...
$ git fetch origin 8233199c8aebb7acb73ab1de36bf4649b3ac8ee3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fftw2
 * [new ref]         8233199c8aebb7acb73ab1de36bf4649b3ac8ee3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8233199 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild