$ git clone -n https://src.fedoraproject.org/rpms/kernel-headers.git /var/lib/mock/f45-build-59-13/root/chroot_tmpdir/scmroot/kernel-headers
Cloning into '/var/lib/mock/f45-build-59-13/root/chroot_tmpdir/scmroot/kernel-headers'...
$ git fetch origin bb9d6e36b7cd3ee54266db86e5a7526b6b056cd2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kernel-headers
 * [new ref]         bb9d6e36b7cd3ee54266db86e5a7526b6b056cd2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bb9d6e3 Linux v7.2-rc1