$ git clone -n https://github.com/xcp-ng-rpms/xen.git /var/lib/mock/v9.0-u-ydi1-11126-29543/root/chroot_tmpdir/scmroot/xen
Cloning into '/var/lib/mock/v9.0-u-ydi1-11126-29543/root/chroot_tmpdir/scmroot/xen'...
$ git fetch origin 97231cb42b9e78dc19f37ab24787717233df01ea:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xen
 * [new ref]         97231cb42b9e78dc19f37ab24787717233df01ea -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 97231cb bump release for test build