$ git clone -n https://src.fedoraproject.org/rpms/free42.git /var/lib/mock/f39-build-2471162-61453/root/chroot_tmpdir/scmroot/free42
Cloning into '/var/lib/mock/f39-build-2471162-61453/root/chroot_tmpdir/scmroot/free42'...
$ git fetch origin a265a08df041e7fef1664cef7b699a90b9cf9bcd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/free42
 * [new ref]         a265a08df041e7fef1664cef7b699a90b9cf9bcd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a265a08 Update to 3.1.4