$ git clone -n https://github.com/xcp-ng-rpms/libssh2.git /var/lib/mock/v8.3-u-pcoval2-10580-29135/root/chroot_tmpdir/scmroot/libssh2
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10580-29135/root/chroot_tmpdir/scmroot/libssh2'...
$ git fetch origin f00bf240ef4e6cb89e3480de8594ce781df56e44:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/libssh2
 * [new ref]         f00bf240ef4e6cb89e3480de8594ce781df56e44 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f00bf24 bump release for test build