$ git clone -n https://github.com/xcp-ng-rpms/libtdb.git /var/lib/mock/v8.3-u-pcoval1-11130-29548/root/chroot_tmpdir/scmroot/libtdb
Cloning into '/var/lib/mock/v8.3-u-pcoval1-11130-29548/root/chroot_tmpdir/scmroot/libtdb'...
$ git fetch origin 53941905ea5414997179a078b2da90d14d63fc6a:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/libtdb
 * [new ref]         53941905ea5414997179a078b2da90d14d63fc6a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5394190 bump release for test build