$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-abourgeois2-8861-27822/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-abourgeois2-8861-27822/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin fab7bedcd9ee6a892a8956bc0c09710ce7829915:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         fab7bedcd9ee6a892a8956bc0c09710ce7829915 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fab7bed bump release for test build