I've recently got a problem. require 'cutorch' doesn't work. But it was ok yesterday, although I have tried to reinstall this package. It doesn't work either.
If you have the same problem, here is the solution.
1.change to you torch home directory. such as '~/torch';
2.run './update.sh';
3.run './install.sh';
4.run 'source ~/.bashrc';
Problem is solved!
Hope it will help you.