Hi, after upgrading, including the switch from /lib to /usr/lib virtualbox still is ok for kernel 3.4.6-1-ARCH, but when I try to build the modules for kernel 3.4.4-rt13-2-rt the vboxbuild command doesn't exist. Until now nothing else seems to be borked. [root@archlinux spinymouse]# uname -a Linux archlinux 3.4.4-rt13-2-rt #1 SMP PREEMPT RT Tue Jul 17 11:32:31 UTC 2012 x86_64 GNU/Linux [root@archlinux spinymouse]# pacman -Qi virtualbox-source Name : virtualbox-source Version : 4.1.18-3 [root@archlinux spinymouse]# vboxbuild bash: vboxbuild: command not found [root@archlinux spinymouse]# ls -hAl /lib lrwxrwxrwx 1 root root 7 Jul 7 12:09 /lib -> usr/lib [spinymouse@archlinux ~]$ uname -a Linux archlinux 3.4.6-1-ARCH #1 SMP PREEMPT Fri Jul 20 08:21:26 CEST 2012 x86_64 GNU/Linux [spinymouse@archlinux ~]$ pacman -Qi virtualbox Name : virtualbox Version : 4.1.18-3 [spinymouse@archlinux ~]$ pacman -Qi virtualbox-ext-oracle Name : virtualbox-ext-oracle Version : 4.1.18-1 Regards, Ralf