build of xen-unstable(c/s-19845) failed for i386/x86_64

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

Hi,
  Build of xen-unstable(c/s-19845) failed for i386/x86_64,details:

 
make[1]: Entering directory `/builddir/build/BUILD/xen-unstable/tools'
set -ex; \
        if test -d 
http://xenbits.xensource.com/git-http/qemu-xen-unstable.git; then \
                rm -f ioemu-dir; \
                ln -sf 
http://xenbits.xensource.com/git-http/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 
http://xenbits.xensource.com/git-http/qemu-xen-unstable.git 
ioemu-remote.tmp; \
                        if [ "f2e0a24d00b2f0c591719bab088fbe3654955066" 
]; then                 \
                                cd ioemu-remote.tmp;                    \
                                git branch -D dummy >/dev/null 2>&1 ||:; \
                                git checkout -b dummy 
f2e0a24d00b2f0c591719bab088fbe3654955066; \
                                cd ..;                                  \
                        fi;                                             \
                        mv ioemu-remote.tmp ioemu-remote; \
                fi; \
                rm -f ioemu-dir; \
                ln -sf ioemu-remote ioemu-dir; \
        fi
+ test -d http://xenbits.xensource.com/git-http/qemu-xen-unstable.git
+ '[' '!' -d ioemu-remote ']'
+ rm -rf ioemu-remote ioemu-remote.tmp
+ mkdir ioemu-remote.tmp
+ rmdir ioemu-remote.tmp
+ git clone http://xenbits.xensource.com/git-http/qemu-xen-unstable.git 
ioemu-remote.tmp
Initialize ioemu-remote.tmp/.git
......
......
Initialized empty Git repository in 
/builddir/build/BUILD/xen-unstable/tools/ioemu-remote.tmp/.git/
+ '[' f2e0a24d00b2f0c591719bab088fbe3654955066 ']'
+ cd ioemu-remote.tmp
+ git branch -D dummy
+ :
+ git checkout -b dummy f2e0a24d00b2f0c591719bab088fbe3654955066
fatal: git checkout: updating paths is incompatible with switching 
branches/forcing
Did you intend to checkout 'f2e0a24d00b2f0c591719bab088fbe3654955066' 
which can not be resolved as commit?
make[1]: *** [ioemu-dir-find] Error 128
make[1]: Leaving directory `/builddir/build/BUILD/xen-unstable/tools'
make: *** [tools/ioemu-dir] Error 2
error: Bad exit status from /var/tmp/rpm-tmp.8933 (%build)

Thanks
Mike.xiao