$ git clone -n https://src.fedoraproject.org/rpms/free42.git /var/lib/mock/f39-build-2236885-53524/root/chroot_tmpdir/scmroot/free42
Cloning into '/var/lib/mock/f39-build-2236885-53524/root/chroot_tmpdir/scmroot/free42'...
$ git fetch origin bb615d476859036bc731bcdb8da50d466c89e3be:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/free42
 * [new ref]         bb615d476859036bc731bcdb8da50d466c89e3be -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bb615d4 Update to 3.1.2