$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-asultanov2-11369-29673/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-asultanov2-11369-29673/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 8a7a777f1b7d9c0b2535b627222eed8f23ee174c:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         8a7a777f1b7d9c0b2535b627222eed8f23ee174c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8a7a777 bump release for test build