[libvirt] build failed with warning " failed to load external entity "api.html.tmp"

[Wenyi Gao]

I got the latest code and build it with following error on Ubuntu 11.10:

......
make  all-am
make[3]: Entering directory `/home/wayne/workspace/project/libvirt/tools'
   CC     virsh-console.o
   CC     virsh-virsh.o
   CCLD   virsh
   GEN    virt-xml-validate
   GEN    virt-pki-validate
make[3]: Leaving directory `/home/wayne/workspace/project/libvirt/tools'
make[2]: Leaving directory `/home/wayne/workspace/project/libvirt/tools'
Making all in docs
make[2]: Entering directory `/home/wayne/workspace/project/libvirt/docs'
Validating api.html
warning: failed to load external entity "api.html.tmp"
make[2]: *** [api.html] Error 1
make[2]: Leaving directory `/home/wayne/workspace/project/libvirt/docs'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/wayne/workspace/project/libvirt'
make: *** [all] Error 2


I think some dependent packages are missed on my build environment. But 
the error information doesn't show some hint. Does anyone know the 
reason? Thanks.

Wenyi Gao