$ git clone -n https://github.com/xcp-ng-rpms/http-nbd-transfer.git /var/lib/mock/v8.3-incoming-8841-27781/root/chroot_tmpdir/scmroot/http-nbd-transfer
Cloning into '/var/lib/mock/v8.3-incoming-8841-27781/root/chroot_tmpdir/scmroot/http-nbd-transfer'...
$ git fetch origin e4db091cde33a3503567914467cd7ed792a96a08:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/http-nbd-transfer
 * [new ref]         e4db091cde33a3503567914467cd7ed792a96a08 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e4db091 8.3: New version 1.7.0