$ git clone -n https://src.fedoraproject.org/rpms/R-Bessel.git /var/lib/mock/f41-build-side-1-3142742-40009/root/chroot_tmpdir/scmroot/R-Bessel
Cloning into '/var/lib/mock/f41-build-side-1-3142742-40009/root/chroot_tmpdir/scmroot/R-Bessel'...
$ git fetch origin 574e169ab0d90a1b4a614e3d3d4bd1dc8d3737ee:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-Bessel
 * [new ref]         574e169ab0d90a1b4a614e3d3d4bd1dc8d3737ee -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 574e169 convert GPLv2+ license to SPDX