$NetBSD$

ERROR: [check-portability.awk] => Found test ... == ...:
ERROR: [check-portability.awk] Scripts/developer_scripts/cgal_build:7: if [ $? == 0 ]; then

--- Scripts/developer_scripts/cgal_build.orig	2024-10-19 01:04:13.000000000 +0900
+++ Scripts/developer_scripts/cgal_build	2025-01-11 08:44:39.321706533 +0900
@@ -4,6 +4,6 @@
 
 [ -r Makefile ] || cmake .
 
-if [ $? == 0 ]; then
+if [ $? = 0 ]; then
   make -f Makefile ${1+"$@"}
 fi