NPM, cannot find ‘graceful-fs’, no matter what I do

Had the same problem. Don’t download npm from aptitude or apt-get.

Instead try:

git clone --depth=1 git://github.com/npm/cli.git
cd cli/scripts
chmod +x install.sh
sudo ./install.sh

saw it here: NPM can’t install appjs. Error: Cannot find module ‘graceful-fs’