$ git clone -n https://github.com/xcp-ng-rpms/libempserver.git /var/lib/mock/v9.0-u-ydi1-11040-29476/root/chroot_tmpdir/scmroot/libempserver
Cloning into '/var/lib/mock/v9.0-u-ydi1-11040-29476/root/chroot_tmpdir/scmroot/libempserver'...
$ git fetch origin b816858169e10f6afc316dcf7a73c8f13aa52850:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/libempserver
 * [new ref]         b816858169e10f6afc316dcf7a73c8f13aa52850 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b816858 bump release for test build