$ git clone -n https://src.fedoraproject.org/rpms/systemd.git /var/lib/mock/f40-build-1897507-25065/root/chroot_tmpdir/scmroot/systemd
Cloning into '/var/lib/mock/f40-build-1897507-25065/root/chroot_tmpdir/scmroot/systemd'...
$ git fetch origin 85035e86c99f5b1fce996f018560716f3fd3cc9e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/systemd
 * [new ref]         85035e86c99f5b1fce996f018560716f3fd3cc9e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 85035e8 Version 255.10