$ git clone -n https://src.fedoraproject.org/rpms/libffi.git /var/lib/mock/f41-build-1045154-19054/root/chroot_tmpdir/scmroot/libffi
Cloning into '/var/lib/mock/f41-build-1045154-19054/root/chroot_tmpdir/scmroot/libffi'...
$ git fetch origin f5f2a00867105873af69d3f60d530031111505dc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libffi
 * [new ref]         f5f2a00867105873af69d3f60d530031111505dc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f5f2a00 Update to libffi-3.4.6