I was getting the weird error Attempt to unlock some_module, which hasn’t been locked.

That’s weird, turns out its a permissions thing.

sudo chown -R $USER ~/.npm
sudo chown -R $USER /usr/local/lib/node_modules

# if your on a OSX and still having problems
sudo chown -R $USER /usr/local

Related External Links:

• Stack Overflow - npm-cannot-install-dependencies-attempt-to-unlock-something-which-hasnt-been