'virsh detach-disk' fails to detach a DVD image from a guest OS

error: Failed to detach disk
error: this function is not supported by the connection driver: This type of device cannot bi hot unplugged

1. Start a guest OS.
2. Attach a DVD image to the guest OS.
   # virsh attach-disk <guest-name> <image-file> hdc --type cdrom --mode readonly
   <The above command should succeed.>
3. Detach the DVD image from the guest OS.
   # virsh detach-disk <guest-name> hdc
   <The above command should fail with error messages>.