~/xen-4.0.1$ make world
(snip)
/bin/sh: gcc: not found
(snip)
make[5]: gcc: Command not found
make[5]: *** [figlet] Error 127
make[5]: Leaving directory `/home/mitty/xen-4.0.1/xen/tools/figlet'
make[4]: *** [default] Error 2
make[4]: Leaving directory `/home/mitty/xen-4.0.1/xen/tools'
make[3]: *** [/home/mitty/xen-4.0.1/xen/xen] Error 2
make[3]: Leaving directory `/home/mitty/xen-4.0.1/xen'
make[2]: *** [install] Error 2
make[2]: Leaving directory `/home/mitty/xen-4.0.1/xen'
make[1]: *** [install-xen] Error 2
make[1]: Leaving directory `/home/mitty/xen-4.0.1'
make: *** [world] Error 2