$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-asultanov1-8988-27896/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-asultanov1-8988-27896/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 2566618a40b33b37655842eee5e55e66651fe769:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         2566618a40b33b37655842eee5e55e66651fe769 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2566618 attempt