node.js - Why does npm install say I have unmet dependencies?

Question

I have a node package. When I run npm install from the package root, it installs a bunch of things, but then prints several error messages that look like this:

npm WARN unmet dependency /Users/seanmackesey/google_drive/code/explore/generator/node_modules/findup-sync/node_modules/glob requires graceful-fs@'~1.2.0' but will load

I must be confused about what exactly npm install does. If it detects a dependency, shouldn't it install it? Under what conditions does it give me error messages like this, and how can I resolve the dependencies?

Answer 1

I believe it is because the dependency resolution is a bit broken, see https://github.com/npm/npm/issues/1341#issuecomment-20634338

Following are the possible solution :

1. Manually need to install the top-level modules, containing unmet dependencies: npm install [email protected]

2. Re-structure your package.json. Place all the high-level modules (serves as a dependency for others modules) at the bottom.

3. Re-run the npm install command.

The problem could be caused by npm's failure to download all the package due to timed-out or something else.

Note: You can also install the failed packages manually as well using npm install [email protected].

Before running npm install, performing the following steps may help:

• remove node_modules using rm -rf node_modules/
• run npm cache clean

Why 'removing node_modules' sometimes is necessary? When a nested module fails to install during npm install, subsequent npm install won't detect those missing nested dependencies.

If that's the case, sometimes it's sufficient to remove the top-level dependency of those missing nested modules, and running npm install again. See