$ git clone -n https://github.com/xcp-ng-rpms/libtalloc /var/lib/mock/v8.3-u-pcoval1-11143-29556/root/chroot_tmpdir/scmroot/libtalloc
Cloning into '/var/lib/mock/v8.3-u-pcoval1-11143-29556/root/chroot_tmpdir/scmroot/libtalloc'...
$ git fetch origin d2188ae48f318eaf45999227eb82e1d1164bea07:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/libtalloc
 * [new ref]         d2188ae48f318eaf45999227eb82e1d1164bea07 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d2188ae bump release for test build