emc2-2:~/emc2.2.1/emc2/src# ./configure
checking installation prefix... /usr/local
checking for RT dir... Using /usr/bin/rtai-config as the RT signature
checking for location of kernel headers... using value from RTS: /usr/src/linux-headers-2.6.12.6-rtai
checking for cc version... found gcc-3.0 in rtai-config
checking for gcc-3.0... no
checking for gcc... gcc
checking for C compiler default output file name... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables...
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ANSI C... none needed
checking how to run the C preprocessor... gcc -E
checking for usability of linux/joystick.h... yes
checking for egrep... grep -E
checking for ANSI C header files... yes
checking for sys/types.h... yes
checking for sys/stat.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for memory.h... yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... yes
checking /usr/src/linux-headers-2.6.12.6-rtai/include/linux/version.h usability... no
checking /usr/src/linux-headers-2.6.12.6-rtai/include/linux/version.h presence... no
checking for /usr/src/linux-headers-2.6.12.6-rtai/include/linux/version.h... no
configure: error: version.h not found - Is the kernel headers package installed ?