$ git clone -n https://src.fedoraproject.org/rpms/BackupPC.git /var/lib/mock/f41-build-side-1-2817883-32992/root/chroot_tmpdir/scmroot/BackupPC
Cloning into '/var/lib/mock/f41-build-side-1-2817883-32992/root/chroot_tmpdir/scmroot/BackupPC'...
$ git fetch origin b03f2170dac4dd24a737f5346099d537772149c1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/BackupPC
 * [new ref]         b03f2170dac4dd24a737f5346099d537772149c1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b03f217 convert GPLv2+ license to SPDX