$ git clone -n https://src.fedoraproject.org/rpms/libdex.git /var/lib/mock/f42-build-side-1-3586663-46924/root/chroot_tmpdir/scmroot/libdex
Cloning into '/var/lib/mock/f42-build-side-1-3586663-46924/root/chroot_tmpdir/scmroot/libdex'...
$ git fetch origin 48a1c3806558db3a900405534fa7d6e9a30d4d49:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libdex
 * [new ref]         48a1c3806558db3a900405534fa7d6e9a30d4d49 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 48a1c38 Update to 0.10.1