>>> Unpacking source...
>>> Unpacking VirtualBox-2.1.4-3-OSE.tar.bz2 to /var/tmp/portage/app-emulation/virtualbox-ose-2.1.4-r1/work
>>> Source unpacked in /var/tmp/portage/app-emulation/virtualbox-ose-2.1.4-r1/work
>>> Preparing source in /var/tmp/portage/app-emulation/virtualbox-ose-2.1.4-r1/work/VirtualBox-2.1.4_OSE ...
>>> Source prepared.
>>> Configuring source in /var/tmp/portage/app-emulation/virtualbox-ose-2.1.4-r1/work/VirtualBox-2.1.4_OSE ...
Checking for environment: Determined build machine: linux.amd64, target machine: linux.amd64, OK.
Checking for kBuild: found, OK.
Checking for gcc: found version 4.3.3, OK.
Checking for as86: found version 0.16.17, OK.
Checking for bcc: found version 0.16.17, OK.
Checking for iasl: found version 20060912, OK.
Checking for xslt: found, OK.
Checking for pthread: found, OK.
Checking for libxml2: found version 2.7.3, OK.
Checking for libxslt: found version 1.1.24, OK.
Checking for libIDL: found version 0.8.12, OK.
Checking for zlib: found version 1.2.3, OK.
Checking for libpng: found version 1.2.35, OK.
Checking for SDL: found version 1.2.13, OK.
Checking for X libraries: found, OK.
Checking for Xcursor: found, OK.
Checking for Qt4: found version 4.4.2, OK.
Checking for Qt4 devtools: found version 4.4.2, OK.
Checking for python support: found version 2.5.4, OK.
Checking for static stc++ library: found, OK.
Checking for ALSA: found version 1.0.17, OK.
Checking for libcap library: found, OK.
Checking for compiler.h: compiler.h not found, OK.
Checking for 32-bit support: OK.

Successfully generated '/var/tmp/portage/app-emulation/virtualbox-ose-2.1.4-r1/work/VirtualBox-2.1.4_OSE/AutoConfig.kmk' and '/var/tmp/portage/app-emulation/virtualbox-ose-2.1.4-r1/work/VirtualBox-2.1.4_OSE/env.sh'.
Source '/var/tmp/portage/app-emulation/virtualbox-ose-2.1.4-r1/work/VirtualBox-2.1.4_OSE/env.sh' once before you start to build VBox:

  source /var/tmp/portage/app-emulation/virtualbox-ose-2.1.4-r1/work/VirtualBox-2.1.4_OSE/env.sh
  kmk

To compile the kernel module, do:

  cd ./out/linux.amd64/release/bin/src/vboxdrv
  make


  +++ WARNING +++ WARNING +++ WARNING +++ WARNING +++ WARNING +++ WARNING +++
  Hardening is enabled which means that the VBox binaries will not run from
  the binary directory. The binaries have to be installed suid root and some
  more prerequisites have to be fulfilled which is normally done by installing
  the final package. For development, the hardening feature can be disabled
  by specifying the --disable-hardening parameter. Please never disable that
  feature for the final distribution!
  +++ WARNING +++ WARNING +++ WARNING +++ WARNING +++ WARNING +++ WARNING +++

Enjoy!
>>> Source configured.
>>> Compiling source in /var/tmp/portage/app-emulation/virtualbox-ose-2.1.4-r1/work/VirtualBox-2.1.4_OSE ...
kmk -j12 -l8 TOOL_GCC3_CC=x86_64-pc-linux-gnu-gcc TOOL_GCC3_CXX=x86_64-pc-linux-gnu-g++ TOOL_GCC3_AS=x86_64-pc-linux-gnu-gcc TOOL_GCC3_AR=x86_64-pc-linux-gnu-ar TOOL_GCC3_LD=x86_64-pc-linux-gnu-g++ TOOL_GCC3_LD_SYSMOD=x86_64-pc-linux-gnu-ld 'TOOL_GCC3_CFLAGS= -O2 -march=core2 -pipe' 'TOOL_GCC3_CXXFLAGS= -O2 -march=core2 -pipe' TOOL_YASM_AS=yasm KBUILD_PATH=/var/tmp/portage/app-emulation/virtualbox-ose-2.1.4-r1/work/VirtualBox-2.1.4_OSE/kBuild all 
Config.kmk:1564: /var/tmp/portage/app-emulation/virtualbox-ose-2.1.4-r1/work/VirtualBox-2.1.4_OSE/out/linux.amd64/release/GCCConfig.kmk: No such file or directory
Config.kmk:2513: *** extraneous `endif'.  Stop.
 * 
 * ERROR: app-emulation/virtualbox-ose-2.1.4-r1 failed.
 * Call stack:
 *               ebuild.sh, line   49:  Called src_compile
 *             environment, line 3567:  Called die
 * The specific snippet of code:
 *       MAKE="kmk" emake TOOL_GCC3_CC="$(tc-getCC)" TOOL_GCC3_CXX="$(tc-getCXX)" TOOL_GCC3_AS="$(tc-getCC)" TOOL_GCC3_AR="$(tc-getAR)" TOOL_GCC3_LD="$(tc-getCXX)" TOOL_GCC3_LD_SYSMOD="$(tc-getLD)" TOOL_GCC3_CFLAGS="${CFLAGS}" TOOL_GCC3_CXXFLAGS="${CXXFLAGS}" TOOL_YASM_AS=yasm KBUILD_PATH="${S}/kBuild" all || die "kmk failed"
 *  The die message:
 *   kmk failed
 * 
 * If you need support, post the topmost build error, and the call stack if relevant.
 * A complete build log is located at '/var/tmp/portage/app-emulation/virtualbox-ose-2.1.4-r1/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/app-emulation/virtualbox-ose-2.1.4-r1/temp/environment'.
 *