[libvirt] libvirt question

Hello，I wrote a program using libvirt API to get vm information like this: /*dom is virDomainPtr type*/ dom=virDomainLookupByID(conn,activeDomains[i]); if(dom!=NULL) printf("%d ----------%s\n",activeDomains[i],dom->name); ...... but when compile it,error occured like this: vm_eraser_detect.c:125:54: error: dereferencing pointer to incomplete type printf("%d ----------%s\n",activeDomains[i],dom->name); what is the reason of it??? thanka a lot! zhunxun(a)gmail.com