Yes, that is true that building +universal on 10.5 won't let you run it on 10.4. You need to take the extra step of setting your sysroot to be the 10.4u SDK.
Change the universal_sysroot line (or add a new one if it's not present):
I haven't tested it myself. I know that ports marked 'universal_variant no' will NOT use that SDK. What you can do is edit your CFLAGS so it's always used (and not just when +universal). Add this to your CFLAGS, CXXFLAGS, and LDFLAGS:
Joined: Jan 2009
2009-01-10 10:49 Post: #11