Oh, actually I was about to mark this invalid, but in fact it is a valid bug that it is trying to compile this bit of code when the AT* were not defined. There is a patch sent and acked upstream to fix this, so I'll mark it confirmed for now.
** Changed in: qemu Status: New => Confirmed -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1014823 Title: qemu-kvm-1.0.1 compilation error on Ubuntu 12.04 Status in QEMU: Confirmed Bug description: CC libhw64/9pfs/virtio-9p-handle.o /usr/src/qemu-kvm-1.0.1/hw/9pfs/virtio-9p-handle.c: In function ‘handle_update_file_cred’: /usr/src/qemu-kvm-1.0.1/hw/9pfs/virtio-9p-handle.c:70:58: error: ‘AT_EMPTY_PATH’ undeclared (first use in this function) /usr/src/qemu-kvm-1.0.1/hw/9pfs/virtio-9p-handle.c:70:58: note: each undeclared identifier is reported only once for each function it appears in /usr/src/qemu-kvm-1.0.1/hw/9pfs/virtio-9p-handle.c: In function ‘handle_lstat’: /usr/src/qemu-kvm-1.0.1/hw/9pfs/virtio-9p-handle.c:87:34: error: ‘AT_EMPTY_PATH’ undeclared (first use in this function) /usr/src/qemu-kvm-1.0.1/hw/9pfs/virtio-9p-handle.c: In function ‘handle_symlink’: /usr/src/qemu-kvm-1.0.1/hw/9pfs/virtio-9p-handle.c:314:62: error: ‘AT_EMPTY_PATH’ undeclared (first use in this function) /usr/src/qemu-kvm-1.0.1/hw/9pfs/virtio-9p-handle.c: In function ‘handle_link’: /usr/src/qemu-kvm-1.0.1/hw/9pfs/virtio-9p-handle.c:337:45: error: ‘AT_EMPTY_PATH’ undeclared (first use in this function) /usr/src/qemu-kvm-1.0.1/hw/9pfs/virtio-9p-handle.c: In function ‘handle_chown’: /usr/src/qemu-kvm-1.0.1/hw/9pfs/virtio-9p-handle.c:373:58: error: ‘AT_EMPTY_PATH’ undeclared (first use in this function) make[1]: *** [9pfs/virtio-9p-handle.o] Error 1 make: *** [subdir-libhw64] Error 2 It compiled okay on 11.04. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1014823/+subscriptions