Don't set -arch flags; MacPorts sets them already.
--- wscript.orig	2019-01-09 16:40:04.000000000 -0600
+++ wscript	2020-10-25 04:16:52.000000000 -0500
@@ -195,8 +195,6 @@
         ctx.env['cshlib_PATTERN'] = 'lib%s.dll'
 
     if target_platform == 'darwin' and ctx.options.enable_fat:
-        ctx.env.CFLAGS += ['-arch', 'i386', '-arch', 'x86_64']
-        ctx.env.LINKFLAGS += ['-arch', 'i386', '-arch', 'x86_64']
         MINSDKVER="10.4"
         ctx.env.CFLAGS += [ '-mmacosx-version-min=' + MINSDKVER ]
         ctx.env.LINKFLAGS += [ '-mmacosx-version-min=' + MINSDKVER ]