$ git clone -n https://github.com/xcp-ng-rpms/sm.git /var/lib/mock/v8.3-incoming-10740-29278/root/chroot_tmpdir/scmroot/sm
Cloning into '/var/lib/mock/v8.3-incoming-10740-29278/root/chroot_tmpdir/scmroot/sm'...
$ git fetch origin e8726c50b7b9e6b3e39bb1c789fdeae69cb2bc14:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/sm
 * [new ref]         e8726c50b7b9e6b3e39bb1c789fdeae69cb2bc14 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e8726c5 Merge pull request #89 from xcp-ng-rpms/update-to-3.2.12-17