title: CUDA: nvcc cannot be detected though installed
body: <p>I successfully installed CUDA 7.0 on ubuntu(ami instance), but when I typed 'nvcc -version', it told me that</p>
  
  <pre><code>The program 'nvcc' is currently not installed. You can install it by typing:
  apt-get install nvidia-cuda-toolkit
  You will have to enable the component called 'multiverse'
  </code></pre>
  
  <p>That's weird since the installation was successful in /usr/local and I've added CUDA 7.0 to my path. I've also tried rebooting my instance then typing in the same command and it didn't work. I'm also sure that the driver for my GPU is correctly. (same error occurs when I use theano to run nvcc test)</p>