$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-gtn1-10242-28817/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-gtn1-10242-28817/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 517d2ec869e144c6aeb5f1ced3647cfe34af8813:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         517d2ec869e144c6aeb5f1ced3647cfe34af8813 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 517d2ec bump release for test build