$ git clone -n https://gitee.com/src-opencloudos-rpms/perl-bignum.git /var/lib/mock/dist-oc9-build-43985-14591/root/chroot_tmpdir/scmroot/perl-bignum
Cloning into '/var/lib/mock/dist-oc9-build-43985-14591/root/chroot_tmpdir/scmroot/perl-bignum'...
$ git fetch origin oc9:KOJI_FETCH_HEAD
From https://gitee.com/src-opencloudos-rpms/perl-bignum
 * [new branch]      oc9        -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9feaa84 import perl-bignum-0.66-3.tl4