$ git clone -n https://src.fedoraproject.org/rpms/libijs.git /var/lib/mock/f40-build-2227945-53055/root/chroot_tmpdir/scmroot/libijs
Cloning into '/var/lib/mock/f40-build-2227945-53055/root/chroot_tmpdir/scmroot/libijs'...
$ git fetch origin c7af5c81f517e87415e20a1b9e3ffd9c304371ea:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libijs
 * [new ref]         c7af5c81f517e87415e20a1b9e3ffd9c304371ea -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c7af5c8 Adjust patch for separated libijs