$ git clone -n https://github.com/xcp-ng-rpms/libtalloc /var/lib/mock/v8.3-u-pcoval1-11028-29461/root/chroot_tmpdir/scmroot/libtalloc
Cloning into '/var/lib/mock/v8.3-u-pcoval1-11028-29461/root/chroot_tmpdir/scmroot/libtalloc'...
$ git fetch origin 04c8e6c939fe63264ff842b9f071b9e1b0a4ffc0:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/libtalloc
 * [new ref]         04c8e6c939fe63264ff842b9f071b9e1b0a4ffc0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 04c8e6c bump release for test build