$ git clone -n https://github.com/xcp-ng-rpms/libempserver.git /var/lib/mock/v9.0-u-ydi1-10980-29425/root/chroot_tmpdir/scmroot/libempserver
Cloning into '/var/lib/mock/v9.0-u-ydi1-10980-29425/root/chroot_tmpdir/scmroot/libempserver'...
$ git fetch origin defa787887d181bbd67951d21f8853300f6d31b4:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/libempserver
 * [new ref]         defa787887d181bbd67951d21f8853300f6d31b4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at defa787 bump release for test build