not what you are thinking!  remove all the libmap.a?s on mk nuke.

Reference: /n/atom/patch/applied2013/mapnuke
Date: Wed Jun 19 02:07:02 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/map/mkfile	Wed Jun 19 02:06:40 2013
+++ /sys/src/cmd/map/mkfile	Wed Jun 19 02:06:40 2013
@@ -29,5 +29,5 @@
 	cp mapdemo.rc /rc/bin/mapdemo
 
 clean nuke:V:
-	@{ cd libmap; mk clean }
+	@{ cd libmap; mk nuke }
 	rm -f *.[$OS] [$OS].out y.tab.? y.debug y.output $TARG