$ git clone -n https://github.com/xcp-ng-rpms/xapi /var/lib/mock/v8.3-u-psafont2-10244-28819/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-psafont2-10244-28819/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin bc6797db31ea9092aba162f3c0e63cfff0e4d4c0:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         bc6797db31ea9092aba162f3c0e63cfff0e4d4c0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bc6797d bump release for test build