difficulty cross-compiling on Leopard for Tiger

[Zachary Fine]

Greetings all,

I'm trying to cross-compile php5, lighttpd, and mysql5 on a MacBook  
Pro running OS X 10.5.2, and I plan to transfer the resulting binaries  
over to run on my AppleTV box. The AppleTV runs a slimmed-down version  
of OS 10.4 Tiger, and seems to run <10.4.8 binaries just fine. Running  
'uname -a' on my AppleTV box results in the following output:

Darwin AppleTV.local 8.8.2 Darwin Kernel Version 8.8.2: Mon Jan 29  
18:57:29 PST 2007; root:xnu-792.94.18~1/RELEASE_I386 i386 i386

I first tried just copying the lighttpd and php5 that I'd compiled on  
my Leopard MacBook Pro over to the AppleTV and running them, but the  
binaries are incompatible:

> bash-2.05b$ ./php-cgi
> dyld: unknown required load command 0x8000001C
> Trace/BPT trap


Through a process of research, trial and error, I made the following  
adjustments to macports.conf and variants.conf.

I added the following lines to 'macports.conf':
universal_target       10.4
universal_sysroot      /Developer/SDKs/MacOSX10.4u.sdk
mmacosx-version-min    10.4

and the following to variants.conf:
+darwin_8 +i386 +universal

I uninstalled all ports, and was able to get my lighttpd and mysql5 to  
install (using the command "sudo port install lighttpd +cml +davprops  
+mysql5 +ssl") but php refuses to compile:

> [zachmbp:~] zach% sudo port install php5 +fastcgi +imap +macosx  
> +mysql5 +pcntl +pear +sqlite +tidy
> Error: Error executing universal: Default universal variant only  
> works with ports based on configure
> Error: Unable to execute port: Error evaluating variants

I'm tempted to just give up on my cross-compilation effort, set up  
10.4.8 on a partition on a firewire drive, and compile using macports  
on that. But it feels like it should be possible to get this working,  
and I don't really want to have to keep 10.4.8 around any time I need  
to compile something for an older system.

Thanks for any help or information.

-Zach Fine
zach at zachfine.com