I just shared two documents with all recipient in this thread. I planned to first reply to this thread to explain the purpose of that two documents, but I checked to send notification by accident. *ouch*
The document titled "Cross-compile EAPI draft" is to document the proposed HDEPEND EAPI draft, and added some possible required variables for proper supporting cross-compiling. Correction and comments are welcome, all of you in the CC list have edit permission to it.
The other document titled "cross-compile troubles" describe the trouble I met while hacking with Paludis. Some of the problems are already properly fixed in the current portage-based build flow that I'm just repeating the same fix with Paludis, while some of the problems are real problems that is hidden by implementation-defined behavior of portage (for example, order of merging package) or other toolchain, those packages should be fixed properly for better deterministic behavior. This document is more like a personal note. I'm trying to make it more complete to document all the fix we did for cross-compile, so it gives a better picture for new people to hack on our build system, and also helps us to design the PMS to be more cross-compile friendly. Again, any correction and comments are welcome.