git ls-tree -r HEAD |
                sed -e "s/^/:/" -e "
                        /       caskly/{
-                               s/      caskly/ $_z40 D&/
+                               s/      caskly/ $ZERO_OID D&/
                                s/blob/000000/
                        }
                        /       nitfol/{
-                               s/      nitfol/ $_z40 $T_letter&/
+                               s/      nitfol/ $ZERO_OID $T_letter&/
                                s/blob/100644/
                        }
                        /       rezrov.bozbar/{
-                               s/      rezrov.bozbar/ $_z40 D&/
+                               s/      rezrov.bozbar/ $ZERO_OID D&/
                                s/blob/000000/
                        }
                        /       xyzzy/{
-                               s/      xyzzy/ $_z40 D&/
+                               s/      xyzzy/ $ZERO_OID D&/
                                s/blob/000000/
                        }
                        /       yomin/{
-                           s/  yomin/ $_z40 T&/
+                           s/  yomin/ $ZERO_OID T&/
                                s/blob/160000/
                        }
                "
        } >expect &&
        {
                cat expect
-               echo ":100644 160000 $_empty $_z40 T    yonk"
-               echo ":100644 000000 $_empty $_z40 D    zifmia"
+               echo ":100644 160000 $_empty $ZERO_OID T        yonk"
+               echo ":100644 000000 $_empty $ZERO_OID D        zifmia"
        } >expect-files &&
        {
                cat expect
-               echo ":000000 160000 $_z40 $_z40 A      yonk"
+               echo ":000000 160000 $ZERO_OID $ZERO_OID A      yonk"
        } >expect-index &&
        {
                echo "100644 $_empty 0  nitfol"