$ git clone -n https://src.fedoraproject.org/rpms/exiv2.git /var/lib/mock/f41-build-858164-168319/root/chroot_tmpdir/scmroot/exiv2
Cloning into '/var/lib/mock/f41-build-858164-168319/root/chroot_tmpdir/scmroot/exiv2'...
$ git fetch origin 30da42e887e3b379d557183cbd539c7a3a099d77:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/exiv2
 * [new ref]         30da42e887e3b379d557183cbd539c7a3a099d77 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 30da42e 0.28.3