Building a cross compiler on Mac OS X

[Vroem]

I have a couple of fairly new macs and I would like to use them to help compiling gentoo on our 'inferior' i686 machines. So I started follwoing the instructions to build a cross compiler.
I got stuck after doing these steps:

• adding cross-i686-pc-linux-gnu to /etc/portage/profile/categories
• setting up PORTDIR_OVERLAY and making links to the directories of the 4 relevant ebuilds (binutils, gcc, linux26-headers, glibc) in /usr/local/portage/cross-i686-pc-linux-gnu/
• none of these packages have ~ppc-macos keywords
  -> allowed portage to use the ~ppc ebuilds in /etc/portage/package.keywords

  Code: Select all

  cross-i686-pc-linux-gnu/binutils ~ppc
  cross-i686-pc-linux-gnu/gcc ~ppc
  cross-i686-pc-linux-gnu/linux26-headers ~ppc
  cross-i686-pc-linux-gnu/glibc ~ppc

• binutils compiled without errors:

  Code: Select all

  $ emerge cross-i686-pc-linux-gnu/binutils

• tried emerging gcc with USE=nocxx but it needed glibc so I skipped this for later
• Here I got stuck:

  Code: Select all

  $ ARCH=i686 emerge cross-i686-pc-linux-gnu/linux26-headers

  this resulted in:
  Makefile:431: /private/var/tmp/portage/linux26-headers-2.6.8.1-r2/work/linux-2.6.8.1/arch/i686/Makefile: No such file or directory
  
  So I tried the stable ppc version of linux26-headers but surprise: blocked by sys-libs/libsystem!

Is this even worth trying?