$ git clone -n https://src.fedoraproject.org/rpms/R-usethis.git /var/lib/mock/f40-build-1930481-25111/root/chroot_tmpdir/scmroot/R-usethis
Cloning into '/var/lib/mock/f40-build-1930481-25111/root/chroot_tmpdir/scmroot/R-usethis'...
$ git fetch origin 86ebb30cab5d46521f0e30b7cc1575e71e9e40f2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-usethis
 * [new ref]         86ebb30cab5d46521f0e30b7cc1575e71e9e40f2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 86ebb30 Update to latest version