$ git clone -n https://src.fedoraproject.org/rpms/step.git /var/lib/mock/f42-build-side-1-3555718-46656/root/chroot_tmpdir/scmroot/step
Cloning into '/var/lib/mock/f42-build-side-1-3555718-46656/root/chroot_tmpdir/scmroot/step'...
$ git fetch origin 7eb1d939b97097b26084bf3f105274e2b79f5223:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/step
 * [new ref]         7eb1d939b97097b26084bf3f105274e2b79f5223 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7eb1d93 25.04.2