$ git clone -n https://gitee.com/src-opencloudos-rpms/thunderbird /var/lib/mock/dist-oc8-firefox-build-57208-15494/root/chroot_tmpdir/scmroot/thunderbird
Cloning into '/var/lib/mock/dist-oc8-firefox-build-57208-15494/root/chroot_tmpdir/scmroot/thunderbird'...
$ git fetch origin oc8:KOJI_FETCH_HEAD
From https://gitee.com/src-opencloudos-rpms/thunderbird
 * [new branch]      oc8        -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7f47986 debrand