Hi,
    I just downloaded Xen4.0 from:    
http://www.xen.org/products/xen_source.html 
   Trying=0A to build:
    Create xen entries under /sys/hypervisor 
=0A(XEN_SYS_HYPERVISOR) [Y/n/?] y
    #
    # configuration 
written to =0A.config
    #
    make-3.79.1-p7[3]: Leaving 
directory =0A`/foo/xen40/xen-4.0.0/linux-2.6-pvo=
    ps.git'
    
make-3.79.1-p7 -C =0Abuild-linux-2.6-pvops_x86_64 ARCH=3D$(sh 
buildconfigs/=
    select-linux-arch =0Alinux-2.6-pvops.git) prepare
 
   select-linux-arch: x86
    make-3.79.1-p7[3]:=0A Entering 
directory `/foo/xen40/xen-4.0.0/build-linux-=
    2.6-pvops_x86_64'
 
   Makefile:7:=0A *** first argument to `word' function must be greater 
than 0=
    .=A0 Stop.
    make-3.79.1-p7[3]:=0A Leaving directory
 `/foo/xen40/xen-4.0.0/build-linux-2=
    .6-pvops_x86_64'
    
make-3.79.1-p7[2]:=0A *** 
[build-linux-2.6-pvops_x86_64/include/linux/autoc=
    onf.h] Error 2
 
   make-3.79.1-p7[2]:=0A Leaving directory=0A `/foo/xen40/xen-4.0.0'
-
 Ignored:
    make-3.79.1-p7[1]: *** =0A[linux-2.6-pvops-install] 
Error 2
    make-3.79.1-p7[1]: Leaving =0Adirectory 
`/foo/xen40/xen-4.0.0'
    make-3.79.1-p7: *** =0A[install-kernels] 
Error 1        
    The Makefile is auto generated as in: 
       
    > cat 
=0A/foo/xen40/xen-4.0.0/build-linux-2.6-pvops_x86_64/Makefile=20
    #
 =0AAutomatically generated by 
=0A/foo/xen40/xen-4.0.0/linux-2.6-pvops.git=
    /scripts/mkmakefile:
 don't edit    
    VERSION=0A =3D 2
    PATCHLEVEL =3D 6 
   
    lastword =3D $(word $(words $(1)),$(1))=A0=A0 
<----------------------------=
    - line 7
    makedir=0A :=3D
 $(dir $(call lastword,$(MAKEFILE_LIST)))    
    MAKEARGS :=3D 
-C =0A/foo/xen40/xen-4.0.0/linux-2.6-pvops.git
    MAKEARGS +=3D 
O=3D$(if =0A$(patsubst /%,,$(makedir)),$(CURDIR)/)$(patsubst =
    
%/,%,$(makedir))    
    MAKEFLAGS=0A +=3D --no-print-directory 
   
    .PHONY: all $(MAKECMDGOALS
Thanks,
CM