$NetBSD$

long options need two dashes.

--- doc/png/Makefile.in.orig	2025-02-23 20:39:21.000000000 +0000
+++ doc/png/Makefile.in
@@ -1,7 +1,7 @@
 ASYFILES = $(notdir $(filter-out $(wildcard ../latexusage-*.asy),$(wildcard ../*.asy)))
 
 SOURCE = ../asymptote.texi ../version.texi ../options
-ASY = ../asy -dir ../base -config "" -render=0
+ASY = ../asy --dir ../base --config "" --render=0
 
 docdir = $(DESTDIR)@docdir@
 infodir = $(DESTDIR)@infodir@