Atlas

[vincent habchi]

Ryan,

> I don't believe any attempt was ever made to build two separate versions and lipo them together e.g. using the muniversal portgroup, though that would indeed be the required strategy for atlas, since it uses a non-Apple version of GCC which cannot build for multiple architectures simultaneously. You're welcome to see if switching atlas to the muniversal portgroup fixes the issue.

I faintly remember having tried that a while ago, but it fails. There are some issues at stake, I'll dig deeper if you want.

> I also don't know whether any attempt has yet been made to verify whether atlas will in fact build for the non-default build_arch. I assume it builds 32-bit on a GCC that defaults to 32-bit (e.g. Leopard), and 64-bit on a GCC that defaults to 64-bit (e.g. Snow Leopard), but I don't know what happens if the user changes build_arch.

First, one must alter the gcc-4.4 or gcc-4.3 portfile to allow building with the --multilib option, that generates libraries both for 32 and 64bits. I've done that, and it works perfectly, so I don't really know why this option was disabled (as it seems to have been removed at some point). Then, I vaguely think that atlas should be build somehow as a metaport, calling twice the Portfile with a different bitsize, then lipo'ing everything together via an external script.

Vincent