$ git clone -n https://src.fedoraproject.org/rpms/R-geepack.git /var/lib/mock/f38-build-724253-99404/root/chroot_tmpdir/scmroot/R-geepack
Cloning into '/var/lib/mock/f38-build-724253-99404/root/chroot_tmpdir/scmroot/R-geepack'...
$ git fetch origin 8d751516080f95444391d4881cebecefb6b067d0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-geepack
 * [new ref]         8d751516080f95444391d4881cebecefb6b067d0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8d75151 R-maint-sig mass rebuild