$ git clone -n https://github.com/xcp-ng-rpms/sm.git /var/lib/mock/v8.3-u-dtt1-11535-29851/root/chroot_tmpdir/scmroot/sm
Cloning into '/var/lib/mock/v8.3-u-dtt1-11535-29851/root/chroot_tmpdir/scmroot/sm'...
$ git fetch origin 1d06b521bf321b7c680e50e1dc8d7a2d06c58139:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/sm
 * [new ref]         1d06b521bf321b7c680e50e1dc8d7a2d06c58139 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1d06b52 bump release for test build