./unshadow: error while loading shared libraries: libcudart.so.6.5: cannot open shared object file: No such file or directory
First, check your paths. An example .bashrc might look like (64bit system):
If you are still getting the shared library error, then check /etc/ld.so.conf.
Add the path to your cuda library: /usr/local/cuda/lib64
Now try running unshadow again, and the problem should be fixed.