$ git clone -n https://src.fedoraproject.org/rpms/primecount.git /var/lib/mock/f45-build-28925-634/root/chroot_tmpdir/scmroot/primecount
Cloning into '/var/lib/mock/f45-build-28925-634/root/chroot_tmpdir/scmroot/primecount'...
$ git fetch origin a10c47d1d54e23b97889dca0b5bf9ccc644bdb3b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/primecount
 * [new ref]         a10c47d1d54e23b97889dca0b5bf9ccc644bdb3b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a10c47d Fix source tarball