make: Entering directory `/usr/src/linux-2.6.27'
  CC [M]  /usr/src/hg/xen-unstable.hg/unmodified_drivers/linux-2.6/platform-pci/evtchn.o
<command-line>: warning: "__XEN_INTERFACE_VERSION__" redefined
<command-line>: warning: this is the location of the previous definition
In file included from <command-line>:0:
./include/linux/autoconf.h:145:1: warning: "CONFIG_XEN_COMPAT" redefined
<command-line>: warning: this is the location of the previous definition
In file included from include/linux/mm.h:40,
                 from include/asm/mach-xen/asm/pci.h:4,
                 from include/linux/pci.h:1026,
                 from /usr/src/hg/xen-unstable.hg/unmodified_drivers/linux-2.6/platform-pci/platform-pci.h:25,
                 from /usr/src/hg/xen-unstable.hg/unmodified_drivers/linux-2.6/platform-pci/evtchn.c:37:
include/asm/mach-xen/asm/pgtable.h:50:1: warning: "_PAGE_NX" redefined
In file included from include/asm/mach-xen/asm/synch_bitops.h:11,
                 from include/xen/evtchn.h:40,
                 from /usr/src/hg/xen-unstable.hg/unmodified_drivers/linux-2.6/platform-pci/evtchn.c:34:
/usr/src/hg/xen-unstable.hg/unmodified_drivers/linux-2.6/compat-include/xen/platform-compat.h:107:1: warning: this is the location of the previous definition
In file included from include/linux/mm.h:40,
                 from include/asm/mach-xen/asm/pci.h:4,
                 from include/linux/pci.h:1026,
                 from /usr/src/hg/xen-unstable.hg/unmodified_drivers/linux-2.6/platform-pci/platform-pci.h:25,
                 from /usr/src/hg/xen-unstable.hg/unmodified_drivers/linux-2.6/platform-pci/evtchn.c:37:
include/asm/mach-xen/asm/pgtable.h:274: error: expected ‘)’ before numeric constant
make[2]: *** [/usr/src/hg/xen-unstable.hg/unmodified_drivers/linux-2.6/platform-pci/evtchn.o] Error 1
make[1]: *** [/usr/src/hg/xen-unstable.hg/unmodified_drivers/linux-2.6/platform-pci] Error 2
make: *** [_module_/usr/src/hg/xen-unstable.hg/unmodified_drivers/linux-2.6] Error 2
make: Leaving directory `/usr/src/linux-2.6.27'