First, sorry for my english, any suggestion is appreciated.

GCC 4.1.2 shipped with Slackware 12.0 is bad for compiling qemu and
VirtualBox OSE.

The only solution: use a test installation, add xerces and xalan and downgrade
gcc and g++ from "slackware-12.0/pasture/gcc-3.4.6".

Added 30/12/2007:
I discovered another problem, iasl won't compile with flex > 2.5.33 (I updated it with 2.5.35 from Slacky repository), so another downgrade to the standard slackware package.

Added 05/05/2008:
Yes! I finally got it compiled with gcc 4. I'm a little disapponted because I read the notice in the recompiler only at version 1.6.0 on Slackware 12.1, but now (on 12.1) VirtualBox compiles everything against gcc 4.2.3.
The magic is the file LocalConfig.kmk that must reside in the directory VirtualBox-<version> and change the compiler only for the component that need gcc 3 (I have to tell you that you need gcc 3.4.6 installed?).
In the file there is only one line:
VBOX_RECOMPILER_OP_GCC = gcc-3.4.6

Now I can tell I'm a real hacker because I know how to read! :-p

Added 09/09/2008
I forgot to update this document, but from version 1.6.4 (as I can remember) everything builds with gcc 4.1.2, so no more build dependencies.

IMPORTANT NOTICE !!!!!!!!
USE ONLY A TEST INSTALLATION, I'M NOT RESPONSIBLE FOR ANY DAMAGE DONE TO YOUR
SYSTEM !!!!!!!!

(I built the package in a virtual machine, it's slower but snapshots are the
safest way to build and rebuild and rebuild to correct errors)

Davide Locatelli (l.davide_AT_tiscali.it)