Someone

 * qemu requires gcc-3 in order to build and work correctly
 * please compile it switching to gcc-3.
 * We are aware that qemu can guess a gcc-3 but this feature
 * could be harmful.

!!! ERROR: app-emulation/qemu-softmmu-0.9.0 failed.
Call stack:
  ebuild.sh, line 1631:   Called dyn_setup
  ebuild.sh, line 703:   Called qa_call 'pkg_setup'
  ebuild.sh, line 44:   Called pkg_setup
  qemu-softmmu-0.9.0.ebuild, line 47:   Called die

!!! gcc 4 cannot build qemu