$ git clone -n https://src.fedoraproject.org/rpms/openscad-bosl2.git /var/lib/mock/f43-build-59089634-6571007/root/chroot_tmpdir/scmroot/openscad-bosl2
Cloning into '/var/lib/mock/f43-build-59089634-6571007/root/chroot_tmpdir/scmroot/openscad-bosl2'...
$ git fetch origin dbec6306ca5c1d8aec58c751af9df6cf1592cf1e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/openscad-bosl2
 * [new ref]         dbec6306ca5c1d8aec58c751af9df6cf1592cf1e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dbec630 fedpkg import did not include the source