$ git clone -n https://src.fedoraproject.org/rpms/tin.git /var/lib/mock/f39-build-2165140-50977/root/chroot_tmpdir/scmroot/tin
Cloning into '/var/lib/mock/f39-build-2165140-50977/root/chroot_tmpdir/scmroot/tin'...
$ git fetch origin 461828b8224a05e7ba32991a3a9b2b47135aa9a4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/tin
 * [new ref]         461828b8224a05e7ba32991a3a9b2b47135aa9a4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 461828b update to 2.6.3 (#2255732)