build of xen-unstable(cs:19963 and 19974) failed for i386/x86_64

[mike xiao <mike.xiao@oracle.com>]

Build infomation:
  build of xen-unstable(cs:19963 and 19974) failed for 
i386/x86_64,details as below:

....

make[1]: Entering directory `/builddir/build/BUILD/xen-unstable/tools'
set -ex; \
	if test -d git://xenbits.xensource.com/qemu-xen-unstable.git; then \
		rm -f ioemu-dir; \
		ln -sf git://xenbits.xensource.com/qemu-xen-unstable.git ioemu-dir; \
	else \
		if [ ! -d ioemu-remote ]; then \
			rm -rf ioemu-remote ioemu-remote.tmp; \
			mkdir ioemu-remote.tmp; rmdir ioemu-remote.tmp; \
			git clone git://xenbits.xensource.com/qemu-xen-unstable.git ioemu-remote.tmp; \
			if [ "a42b67ed27a9744a2492c8ffe5c26935bd19ee27" ]; then			\
				cd ioemu-remote.tmp;			\
				git branch -D dummy >/dev/null 2>&1 ||:; \
				git checkout -b dummy a42b67ed27a9744a2492c8ffe5c26935bd19ee27;	\
				cd ..;					\
			fi;						\
			mv ioemu-remote.tmp ioemu-remote; \
		fi; \
		rm -f ioemu-dir; \
		ln -sf ioemu-remote ioemu-dir; \
	fi
+ test -d git://xenbits.xensource.com/qemu-xen-unstable.git
+ '[' '!' -d ioemu-remote ']'
+ rm -rf ioemu-remote ioemu-remote.tmp
+ mkdir ioemu-remote.tmp
+ rmdir ioemu-remote.tmp
+ git clone git://xenbits.xensource.com/qemu-xen-unstable.git ioemu-remote.tmp
Initialize ioemu-remote.tmp/.git
xenbits.xensource.com[0: 70.42.241.107]: errno=No route to host
fatal: unable to connect a socket (No route to host)
Initialized empty Git repository in /builddir/build/BUILD/xen-unstable/tools/ioemu-remote.tmp/.git/
make[1]: *** [ioemu-dir-find] Error 128
make[1]: Leaving directory `/builddir/build/BUILD/xen-unstable/tools'