$NetBSD$

long options need two dashes.

--- tests/Makefile.orig	2025-02-23 20:39:21.000000000 +0000
+++ tests/Makefile
@@ -10,11 +10,11 @@ all: $(TESTDIRS) $(EXTRADIRS)
 
 $(TESTDIRS)::
 	@echo
-	../asy -dir ../base $@/*.asy
+	../asy --dir ../base $@/*.asy
 
 $(EXTRADIRS)::
 	@echo
-	../asy -dir ../base $@/*.asy
+	../asy --dir ../base $@/*.asy
 
 clean:  FORCE
 	rm -f *.eps