Let's try this. It's BUGGERED.

src/cmd/pic/mkfile

@@ -0,0 +1,38 @@
+<$PLAN9/src/mkhdr
+
+TARG=pic
+OFILES=picy.$O\
+	picl.$O\
+	main.$O\
+	print.$O\
+	misc.$O\
+	symtab.$O\
+	blockgen.$O\
+	boxgen.$O\
+	circgen.$O\
+	arcgen.$O\
+	linegen.$O\
+	movegen.$O\
+	textgen.$O\
+	input.$O\
+	for.$O\
+	pltroff.$O\
+
+HFILES=pic.h\
+	y.tab.h\
+
+YFILES=picy.y\
+
+SHORTLIB=bio 9
+<$PLAN9/src/mkone
+YFLAGS=-S -d
+LEX=9lex
+
+picy.c:	y.tab.c
+	mv $prereq $target
+
+picl.c:	picl.lx
+	$LEX -t $prereq > $target
+
+clean:V:
+	rm -f *.[$OS] [$OS].out y.tab.? y.debug $TARG picy.c picl.c