$ git clone -n https://src.fedoraproject.org/rpms/passim.git /var/lib/mock/f38-build-side-42-init-devel-1407425-31318/root/chroot_tmpdir/scmroot/passim
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1407425-31318/root/chroot_tmpdir/scmroot/passim'...
$ git fetch origin 593538f9ab06536c55f5a468a3cecab7b5c094af:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/passim
 * [new ref]         593538f9ab06536c55f5a468a3cecab7b5c094af -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 593538f New upstream release