$ git clone -n https://src.fedoraproject.org/rpms/dar.git /var/lib/mock/f39-build-1457856-33020/root/chroot_tmpdir/scmroot/dar
Cloning into '/var/lib/mock/f39-build-1457856-33020/root/chroot_tmpdir/scmroot/dar'...
$ git fetch origin fa5d6d64c2dab8607ebde7f057f9b6a0961d8ff4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/dar
 * [new ref]         fa5d6d64c2dab8607ebde7f057f9b6a0961d8ff4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fa5d6d6 - Update to 2.7.12 fixes rhbz#2237082